j

Book °_/

MILK AND CREAM CONTESTS

Washington, D. C.

ERNEST KELLY

In Charge of Market Milk Investigations, and

GEORGE B. TAYLOR

Market Milk Specialist, Dairy Division

UNITED STATES DEPARTMENT OF AGRICULTURE . DEPARTMENT CIRCULAR 53

Contribution from the Bureau of Animal Industry JOHN R. MOHLER, Chief

August, 1919

WASHINGTON : GOVERNMENT PRINTING OFFICE: 1919

MILK AND CREAM CONTESTS.’

CONTENTS. Page. | Page, Contests promote better milk supplies......- 3 | Contests in which samples are taken on the Tw ovukindsjofcontestsS soaceenee once eee 3 Streete. ..ssc5ccccies cece poser eeeee eens ll Methods of scoring milk and cream.........- 4 Collecting the samples. ---..--:.2-.--..-- 12 Score card onmilksos aesecerses ceenccece 4 File card for recording milk scores...... 12 ScoreicardHoricream sec. 4-esso cee esses 6 | Laboratory equipment for conducting con- Contests in which samples are prepared by tests... cesses leis: ose siccies sce ceessesieceert 12 Contestantssnssoset een eere coer ence eeeee 8 | Methods of analyzing and testing............ 14 Preparation of samples.............----- 10 || ePublicitycccecescee- ses ceeeee a aecee eee 25 Shippine‘the sampless2.- as s---- =e o'> 10 Handling samples at destination......... 10

CONTESTS PROMOTE BETTER MILK SUPPLIES.

RIENDLY RIVALRY among milk producers and dealers is an

important feature in the improvement of the milk supplies of cities. Any factor which encourages this rivalry must be given careful consideration by sanitarians and all milk authorities. Since the inauguration of milk and cream contests, in 1906, this method of promoting friendly rivalry has been recognized. At this time, be- sides State and National contests, a number of cities use such means for grading milk supplies.

Milk and cream contests promote competition among the dairy- men, lead to the grading of milk supplies, and through publicity encourage the efforts of producers as well as educate the consumers regarding the value of good milk and where the best can be obtained.

TWO KINDS OF CONTESTS.

Milk and cream contests are of two kinds—one in which the dairy- men prepare their own samples of milk or cream especially for the contest, the date of which is known; the other in which samples are collected on the street without the knowledge of the producers. The first method may or may not indicate the dairymen who gen- erally produce the higher grades of milk. It represents only care in the preparation of samples for definitely known contests. As an educational factor, however, it is very valuable, as it teaches pro- ducers care and cleanliness in the production and handling of milk. Of course, in such contests the dairymen take extraordinary care in the production and preparation of the samples, but there is neverthe- less an educational value, as shown by the fact that dairymen con- testing during several consecutive years usually receive higher scores each succeeding contest. In National and State contests all samples

1 This circular is a revision of Department Bulletin 356. It is of interest to officials and sanitarians concerned in the control of milk supplies of cities and in a general way to producers of market milk,

2

ARR. vofi/24 De v

a ‘Milk and Cream Contests. 3

are, of necessity, prepared samples. The advertising value of a high score is so great that much interest is always aroused.

On the other hand the surprise contest, especially when it repre- sents samples of milk or cream covering a definite period of time, gives a mathematical rating to each producer based on his everyday product, thereby laying the foundation for grading a city’s milk sup- ply. Such contests are valuable in bettering the local milk supply and should be mstituted especially in the smaller cities when labora- tory facilities are available.

There are three classes of entries in milk and cream contests—cer- tified, raw market, and pasteurized. In grading, these classes must be regarded as entirely distinct, and in the report of results each class must be given separately.

METHOD OF SCORING MILK AND CREAM.

The samples are scored for bacteria, flavor and odor, sediment, fat, solids not fat (im case of milk), temperature or acidity (depending on the kind of contest), and the appearance of the bottle and cap. A perfect score is 100, divided as shown in the score cards following:

[Front.] UNITED STATES DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY.

DAIRY DIVISION.

SCORE CARD FOR MILE.

NN te he gare SINS CNT I ahah cect tsa eer RO an eee NS TIA eG nL (OUST) 5 eee od eae SS a a EIXDIUDIGING: access cance cco eh eohsce Se oe Perfect Score be Item score. | allowed. Remarks. EPC ROTI etal cseyaiarsrana avave a) a-<)nisiniciaiSinta.ajeistelecaie's'aialiere 35) i|/esierereretarsre.s Bacteria found per cubic centimeter OME NC OG OR far cas oesenccenicwinaee sum sem V6uleesesaoee' Cowy, bitter, feed, flat, strong, Sediment LOH Servis ener 5 * Ite 5 SO EOL ene 11 Beers Per cent, Sohds not fat 21s) Re aeons Per cent, Temperature (street samples) Degrees, or OD? (Srersiciot ene sis or Acidity (prepared samples) Per cent, Bottle and ca 5 ‘Gon p eweeaenecio Cap, Ota es ccm acccagaes ood sac dels cde caetuts LOOM iis etate vera cet [EES SCO Lee ene eee eh ce mom teh. Re ee EA oh Dt ele Bon hese JMO IGUSEIS'S) OSE es - Ss Se ee Oe ge a - S(SIPROG) Mmmet Lente mt ce solo eee ee Seer be taken eee

ee ee oy

ee a |

NW AOue seis cites toa cic ccc ss'sswseice cos

4 Department Circular 53, U. S. Dept. of Agriculture.

[Back.] DIRECTIONS FOR SCORING.

BACTERIA PER CUBIC CENTIMETER—PERFECT SCORE, 35.

Points.

HOO an GUndele eemeceines seme se cies esa alates 35 20 00125: O00 saiomasiete renee scene saeeinerete eer BOL O00 4 tee eee ore Lea eee 34-0) |325,001=30,000. 2220 ese eee aoe eee ee eee LON 1 o00es.sae8 sotacee ee? EAC 3428) |b30; 001-351 000 sea. oan eee eee oe 1,501-2,000..... fSyae rishi ew cp) ie sei Eee ae 34077) \|| B5t001-40 000rcee <eeneceeesesseecenee eee B 00122: 500! sscanueterss corte ae see eee 34:6: |340,001=45, 00055. -5 25 oases eee eee DEOL S1000 ses cate ee eee 4.5 Aa OOL=50000s Seeker fe Senne seen one 30013; 500 Heine coer eee. ae Sa eeee Sacer 34-40 1'50:001=55;000 s2-ess eeciee ace seeeceeeee eee ase BFOIA00s anata an ee tee ee eer eee 34.-3°|255\001-60;0000>-2¢ 2c. ose see ae te eee AV O04 500 Soe meaceen teens scenes eee asee ene sae 3452 160; 001-69; 00058 omen ceeeee eee eee eee AEEOI'S OOU BE eee aes tte et ee ee 34<();,)165,001-70)/ 000-00 coca ae tae Seen eee SOOT O O00 sac erccee ceenseee eee eres eee cee Eel PUR EU EYGNUN ehorespeconocoosooossococascrcc 6,001 7)000 Lo. fon ce osc o cc ctewese sth oe-cclseicene B86, | WhO) CO 80) 000 soa cceee coe eee ae WiQO1-8;000 2.5.2 -ens. coe oe fae eee. SB ee eee eer ee on ee a B.001-9 000. cence Se eh oe eae eee O00 oracle ce noe ear Gece --- 9,001-10,000...... Say yar ie ein Uo er aes oe co saemeacocbsee 10 001-11 000 32.8 95,001-100,000 ojainia sinioin iain loinie\oimim mini [e)a ma wierw ales

: oer A aE SOS os SA RR Ste Sp a TOOFO00T=120 000 we a efor aiesiatesssie ieee eee 11,001-12,000 ce cieicje cece siecicieenececececece=e=ene 32.6 120,001-140,000 Siege! eae ah tLe ey ae Oe 12,001-13,000......---------+-2+222eeee sree eee BZ, 4740001160 000's 25) o-- ene eee 13,001-14,000....--.--.------+--------- 22-2 +e 32) 241 160;001=180/000) 2. tesa. eee 12:00E-15 0008228 a eek ee eee ee 3220:"|/°180;0012200,000s.0 0122 02.ce ee Ae eee 15001220000. con eee ne ee ee ee 31°) IccAbove.200,000. f 4-222.) ee

S .

Note.—When the number of bacteria per cubie centimeter exceeds the local legal limit the score shall

be 0. FLAVOR AND ODOR—PERFECT SCORE, 15.

Deductions for disagreeable or foreign odor or flavor should be made according to conditions found.

When possible to recognize the cause, it should be described under ‘‘ Remarks.”

SEDIMENT—PERFECT SCORE, 10.

Examination for sediment may be made by means of a sediment tester and the resulting cotton disks compared with standards; or the sediment may be determined by examination of the bottom of the milk in the bottle. In the latter case the milk should stand undisturbed for at least an hour before the exami- nation. Raise the bottle carefully in its natural upright position until higher than the head. Tip slightly and observe the bottom of the milk with the naked eye or by the aid of a reading glass. The presence of the slightest movable speck makes a perfect score impossible. Further deductions should be made ac- cording to the amount of dirt found. When possible, the nature of the dirt should be described under

“Remarks.”’ Fat IN MILK—PERFECT Score, 15.

Points. 40;per:centiandOvercascnese ose ee see cee ees 150 aor DCLUCON bas selanacmerinclnee seeeaise eee SOIPCMCONGma ones sce case sees ecce eee ete 145)| 48-2) Denicentaneseeecescceee cetera 3:83 Pen Comte.ceee <22c ans eiceeeeaes Seeieee fees ete IBA roel percent sen cemecmescee esses see meee SKDOL CONG cs ccjiss aisties soso seiieenoe ce spiiserieces 12 Ae O/POL CoN ba acme cc sepeeneaeceec eee cece S.GipernCent.2 ei scesmccace sisson cee er cecaceciee IM a2 Oy PericCents ance de mciseee eee eect OS. D DCLCONGs «ca ntee sea oie ease teeter eee cee 100 Pessithant2:9ipericentiee.<to-e so eeeeeee eee SA PCLICONE. oe c.clseicicts c/oreis viele os tel sisisieis's sais elelerers 90

NotEe.—When the per cent of fat is less than the local legal limit the score shall be 0.

SoLtips Not Fat—PERFECT ScorE, 15.

Points. Simpencenvan GOVer access cece ae estates 15uleSiaspern Cent: coe see-eoeeas eect ae eereeeee SIGIDERCENbiscc csc crcl s csewemee cee oeseeses 137 ES periCenter <- cece oece eee asec eee eee SOIPCHCeN be ecaseee cre ceocecc eee eee LM | MS speI Centres seececre ese aiaae cence SA MeTaCON Varese ojs0neiantein veins seco hen eee 9) |bess than'S per Cents acsc--- eee eee eto S.SIPCL CONG 5 ac cwisieinccieisie = See ciine See cine eee aes 7

Note.—When the per cent of solids not fat is less than the local legal limit the score shall be 0.

TEMPERATURE (STREET SAMPLES)—PERFECT SCORE, 5.

Points. | 50° Bor below: scenseceseccc sn mais sears since Ditte 5 atO OOmasteieiscieiotecicier iene sisters enantio inreoines BISTOMSS Es cocicccica slow cacs canes salsa eemaseceness AW A DOVE.60 >< « cjc%:0ie aic-c1ers © ainorereters ols slerein cleialelarsie

OAL OPO Orerereieleistels «iste sle/slalleinisielatelersiaialaiateiais/=ielaielsi—'— 3

Points.

Points.

Points.

Milk and Cream Contests. 5

[Back—Continued.]

ACIDITY (PREPARED SAMPLES)—PERFECT SCORE, 5.

Points. Points. Oren Colt OMLGSS a2 ewig eaters sea at aac a= D: (0:23 PORCONGS 2.52.5 5iszon Sat Sees oaceseen cate 2 OATS NEG CON. core nctneinn< ccieiwe cielo oc siaceasiciarniee | 102245 DEL COUUs as ook selene ce aoe cectenec see sametasae 1 (EZ 2VOL COM tsce ence nce ch wesc ence vect ce scoees 3 | More than 0.24 per cent............-:.22ce00e- 0

BOTTLE AND CaP—PERFECT SCORE, 5.

Deductions in score should be made for dirty or chipped bottles or for caps which do not cover the lips of the bottles or do not fit properly in the cap seats.

[| Front.) UNITED STATES DEPARTMENT OF AGRICULTURE, BUREAU OF ANIMAL INDUSTRY. DAIRY DIVISION.

a

SCORE CARD FOR CREAM.

Dalen eee erst Syst 5 5, 3 9S ois csi chorsjers eee Sai he craps oreo Swlded aa’ Seah seed cues’ F

(CYS Ess SR ea ea Exhibit No......-..

Perfect | Score. ay Item. score. | allowed. Remarks. 1 SHE CCLICL RIE ns Fa eae 35) |-eoeess eat Bacteria found per cubic centime- TT ee ey Sy ete at 2, HEC crea TDIE (07 e500 06 (0) eee er 20) [Lee nce nse Cowy, bitter, feed, flat, strong.......... BOG MICK Gace aot <a Sten se Aan see nee LOU etree Ses Wears ae eae se ee ree ae a ee ace ee ee ee EE eee eae Sas eRe cc arels ye he cee ene 20) |i occa shee Peles eC ee ee Re ee ee Temperature (street samples)............--- ONE Saat gee UD GR Tec Se eee tee oa oe ee or or Acidity (prepared samples). ................ IRGI CON Uae etre bere cease ac hoo soe IBOLGG ANG CAPi son. Sc cccicceccwcseeecaseee Dh | epee ee CAD ee neers Soe arate nen aees sooee gales IBOUULG Soe eaten sciines sme sieercte daa see OU Chic le ope eee a aes aasans Sarees LOW ener oe 1B 5c] Wul ow i}f0) ag Sen A da ee ee cee ANGGWG NSCS G esas tess tee eee Se ee oP oe ee re a ae PNT Pa ERTL a ote eta, a eR a aS ae ease Judges Date...<:0's Bea Sawa erp (orn ies cies <

(OVER.]

6 Department Circular 53, U. S. Dept. of Agriculture.

[Back.] DIRECTIONS FOR SCORING.

BACTERIA PER CUBIC CENTIMETER—PERFECT SCORE, 35.

Points. Points. Under 500 ss cccescpien coc same’ scegiseetse = tai 35 25,001-30) 000 Sse neccem sceeecees ees ent eceeecee 29 BOL=1 00022 sees terciess focensateet ess smscma es S459 13000135000 sreneeecessecoencetoeeee ee eceeeee 28 1L001 =1500M Ee viicc acces aces coeee me acee sees a-— $428:|/35,001=40) 000s. meescsececescse teen ease es aeee 27 T5012 000 255. sees cromceeine Sor sepeieeinee sates 34./7)| 4000145; 0005: sectac cioeec cee ene ce torte ates 26 DIQ0IH23500-: 2 <2 -cseca ne weeseecet ee esemseane 3456 ||745,001=50 000! sae saemeee omer coke eee eae 7a 2 501=3, 0002002: 22-5 cee nese see see eee 3425 "|)'50;001=65 000: 222 = sew ccc cccitesces seers 24 35001-3500. 2s S2ca cece tee er ene a oars elena e ae $42401'551001=60000iHee,. = samen osc eee ceae eee eee 23 $5014 0002. oct 22 nascent e eo ae ees 34.53'\| 60001651000 S232 cen ctcscmccecee emer e eens 22 A O0I=4 S002 See te cnc cise esa ae sel cietiet tester 3452" |65;001-70: 000. ect sae cesicn oxt- ste toscencsee eee 21 45015 000%e cane meester caer see 34 70001-75000! Ss. Ss wjeneecwseeeeecmeeee tees eees 20 Bi001- 6: (00h sate cs teemee enn e et eee ees samen 33.8 | 75,001-80,000......-.-.... Pia BES A se 2 22919 6,001 7,000 452s --mserea sie == eesee tae er 33/67//80;001=85 (000s s- eee eee ee ee eee 18 70018000! ccc cae cwiset seit na criaemciteaas an 3354°1785;001=90' 000 22e se. ee secetnes sce eee eee pees 8001-9000 222s eetem cance cee meee ne sceem aera $3.'27|905001-95 000 ees. scence ccecen cee cence cerns 16 9 ,001-10,000..... 2.2... 002 seen e ee cone e- eee eeee 33 95°001—100 000 eee seeesea ss eeoer eee eee eee 15 10;001 111000 282 onic eae ae te inerrant ets 32°85] 100) 001120000 bee en-ceeacesncecesee eases 12.5 41/001=12'000' 2s. cceceeze neces ee ecs sss anes 325601 120:001=140) 000 Seas saeeeeeeeeeeeeseneee ae 10 12001-13000 Woon je casa sie reine ermreie = viet aici aiai= 325415140; 001—1160) 000 Sam cierac ct soso eer eee eee 7.5 13;001=14 000. oo oo ses ono were winnie sisi cin sisi == === 3252121600011 805 000! =e ctete ete a ratote ate lateral etre 5 14,001=15;000 352: .< < ccciececce mec ce-- see es= 5 -- 32 1'80%001—200 000 Sees ciarciate ertareta ote aine ete eee ore 15 3001=205 000 Seo: seitercajetneesian = aac eee min 31 Above 200,000 5 2.c sec ios Sais em scwssitte wiciele ancteeotstes 0 90;001-25;000! 32-2 si. settee ie tae ee seee a nee 30

Note.—When the number of bacteria per cubic centimeter exceeds the local legal limit, the score shall

be 0. FLAVOR AND ODOR—PERFECT SCORE, 25.

Deductions for disagreeable or foreign odor or flavor should be made according to conditions found. When possible to recognize the cause, it should be described under ‘‘ Remarks.”

SEDIMENT—PERFECT SCORE, 10.

Examination for sediment should be made only after the cream has stood for at least an hour undisturbed in any way. Raise the bottle carefully in its natural upright position, until higher than the head. Tip slightly and observe the bottom of the cream with the naked eye or by the aid of a reading glass. The presence of the slightest movable speck makes a perfect score impossible. Further deductions should be made according to the amount of dirt found. When possible the nature of the dirt should be described under ‘‘ Remarks.”

Fat IN CREAM—PERFECT SCORE, 20.

Points. Points. 25 per Cent Or ADOVE........2cceeeee----- eee e-- 20 19 PerCenl. .asacmecceticcas coerce teeters 17 24 POL Contes seat ncsccase see eee eee aceaeers 19.5) | eUSipericen ts =< sss sec seneceecsecoeeee see eee 16 23 DON CONG stcteremscces iscesceccsea seer eee== 19 Lit PeriGOnl . scciscwcinciseissccieleaicemeccesen sce 12 2ZIDEL CON tccevce coecae se ca stalsce ces emcee 18:57) LO Mei CONUsreacteceiiceisccmocce cee aeieee ee eaaaae 8 ZLMONCOM skew caceccet cecescacetes veeceeseee 18 LOMPCL COM beac seieiacciee cele cies ie isleaieeleeiee eat 4 QO MOT CONT ccs cick secs. o ccc isireaeci neste 17.5,.|hlsess than 5 per/Cents..neeeceencie ce aeenineiste 0

Note.—When the per cent of fat is less than the local legal limit the score shall be 0.

TEMPERATURE (STREET SAMPLES)—PERFECT SCORE, 5.

Points. Points. pOderrees: EsOM DOlOW: «c.scsess cece cece enemas Bell bTALO GO Me mamccae seer cise acces elscteciets aeteteiasme 1 BI TOMDS so sos ea ewele eke s'sie ocelsjsastese ane 2acoe tae 47) |) AD OV.OG0!saeeecne aa toisisicicisietaloisin a's otereleitetetetereteier= 0 DELO Ge rare aicieracielesamesisisine aisles catenins meres 3

AcIDITY (PREPARED SAMPLES)—PERFECT SCORE, 5.

Points. Points. OZ ponicentandiless: oo. cscs seccce clas seen sesseer 5) || 0:23 PeriCONt sean «see se wiscleesWleietsicleieelleleleiese ieee 2 ORZIID ORICON Deca sac eo aictere sa arctactece ere meets 40.24 periCentan eee scenes miem eerie eater 1 O22 MENIGEM Thies on cies 'sewicteseccieme ch cemesee 3) || More than'0'24 per centt-2s. e.ae--oee eee 0

BotTLE AND CAP—PERFECT SCORE, 5,

Deductions in score should be made for dirty, chipped bottles; for caps which do not cover the lips of the bottles or do not fit properly in the cap seats.

Milk and Cream Contests. vi

CONTESTS IN WHICH SAMPLES ARE PREPARED BY CONTESTANTS.

Before definitely announcing the time and details for holding milk and cream contests, the persons in charge should arrange to obtain prizes for the contestants. This is important, since there should be an additional incentive for the producers besides the desire of winning the contests. In local contests such city organiza- tions as the Chamber of Commerce, the Rotary Club, civic leagues, or women’s clubs might be interested in furnishing prizes, such as money, cups, or even dairy equipment. Interested commercial firms may easily be persuaded to give prizes.

After details of the contest are arranged, general publicity can be given through local newspapers. It is best, however, not to depend too much upon this kind of publicity but to send preliminary notices to the dairymen themselves, as a great deal of individual effort usually is needed in interesting the producers. Each pro- spective contestant should receive an entry blank, the filling out and sending in of which must be made prerequisite to the entering of samples of milk or cream in the contest.

SAMPLE ENTRY BLANK.

DEPARTMENT OF HEALTH. GUIYAOR eee eeee eee

OFFICIAL ENTRY BLANK.

MILK AND CREAM CONTEST.

(Place. )

intdentiendirectiOl OL: 23... c0c2ss2cc cess acleecece ose cerees calcawercisioe ane sececls The following classes are provided:

Class I. Raw market milk.

Class II. Certified milk.

Class III. Pasteurized market milk.

Class IV. Raw market cream.

Class V. Pasteurized market cream.

RULES,

1. Competition is open to all milk and cream producers and distributors supply- pete and cream to... c.5'..2-.sesece- tenes

2. Only one entry may be made in any one class.

3. Producers of certified milk are barred from competition in any other class.

4. Allsamples of certified milk must be accompanied with a certificate issued by the medical milk commission under whose supervision the milk is produced.

5. Entries in milk classes consist of 4 pints of milk in pint bottles.

6. Entries in cream classes consist of 4 one-half pints of cream in half-pint bottles.

7. All entries of milk and cream after scoring become the property of the depart- CTO MGANG NOL &..2.725s-< clad celokeus a0s.4-2

8. No contestant will be entitled to placing who does not make answer to each question herein given, sign declaration and forward this official entry blank

(Name.) ( Address.)

8 Department Circular 53, U. S. Dept. of Agriculture.

HOW TO COMPETE,

Milk or cream to compete in this contest must be delivered or shipped, prepaid, to ine order that all milk and cream entered by contestants may be of the same age

when scored, all samples must be produced or prepared on ....... Ga ee ate. and shipped immediately. Bottles should be carefully packed in ice in a proper

shipping box, and this box marked plainly on the inside cover as well as on the out- - side with the owner’s name and address. An official representative of the judges will receive all samples and place them at

once in cold storage. APPLICATION AND QUESTIONS TO BE ANSWERED.

Please enter for me four-(pint):bottles/of, 22522 3355--- <= sees aoe eee to com- } pint) pete in felass( | Msates sence ece we eee ee in accordance with conditions herein prescribed.

. How many cows contr een to the sample of milk entered?). 2... se ae . What kind and quality of feed was given cows daily during the week preceding the productioniofthe sample?ti: 2.22 S22 Sasser ee ks eee <i

wnr

5. What kind of pail was used, small-top or Open?.+i.22425.2:262222 422 6. How were the utensils sterilized? Re ee ee GS ee en Ane NS a 8 = = - -

7. What.method of straining was used? 2.7.52 22.5.2- cess. aoe 8) How was the milk ‘cooled?! o2 22.2 5222) ses Se eee eee eee eee eee

How long:atter milkine?: 25.2.2. .2-c22 22 To what temperature? .......--..-.- 9. Have you previously exhibited milk or cream at any local, State, or National show

10. (Additional for cream). How was the sample separated? .............--.-..- Mee poet oie Seto vets ve ke eee ee How was the separator cleaned? .........-

11. (Additional for certified.) Give name and address of medical milk commission certifying to your products. .22. 0-2 -32 o-c 2 Ses cee ee ae eee ee eee

14,° Did you use a clarifier? 222 22.5 tee ee ee ee ee eee 15. To what temperature was the product heated? .......-.. 2-2-2. ===. -2 eee ee 16. How long wasit held at that'temperature?’2:-.-- 2522225222222. = eee 17. Do you use automatic temperature control and recording thermometers? ........ 18. To what temperature was the product cooled? Jee one a ite Boe oe eee See 19: How was the pasteurizing apparatus cleaned 22... .2- 52-6 seem ee 2 eee Dee isc oacahncet ese , do hereby declare each and every statement in answer to the foregoing questions ‘to be true. I do furthermore declare that the product submitted by me is the pure natural product, free from preservatives, and (for Classes I, II, and IV) that it has not been heated or changed in any way. 1 DE Pee aE Ree ea a es oor EA 8 (Name): nc e.aec ccs Sck she beeen

(Address) fa) dccntecase creo oes Do you wish shipping box returned

at your expense? .......

Milk and Cream Contests. 9

PREPARATION OF SAMPLES.

The person in charge of the contest should issue detailed instruc- tions regarding packing and delivery. Express charges should be paid by consignor. Contests with prepared samples would be fairer and results more valuable if the sample represented the milk of the entire herd. In some contests this is required. Generally, however, entries representing the product of one or more cows may be furnished. Usually great care is taken to obtain the sample under as near sterile conditions as possible. Thorough washing of the udder and the hands of the milker is necessary, and a properly sterilized, small-top pail should be used. Sterile absorbent cotton or filter cloth is the best material to use for straining milk.

It is not advisable to pour the milk, while still warm, into the final container, as the shrinkage when cold leaves some space between the milk and the cap. This may detract from the appearance of the bottle, and churning may result. It is suggested that the milk be strained into a sterile container and cooled, special care being taken to avoid contamination. The milk, after mixing, may then be poured into sterile pint bottles and the caps put on. Caps may be sterilized by dipping into melted paraffin, but care should be taken not to heat the paraffin too much, as it gives off odors at high temperatures. When the cap is placed firmly into the cap seat of the bottle, some melted paraffin may be poured on. The top of the bottle should be protected by means of a cap cover. When filled and capped the bottles must be packed immediately in ice and kept cold but not frozen, until ready for examination. An ice-and-salt mixture for cooling should never be used, as it may freeze the samples.

SHIPPING THE SAMPLES.

If the samples are to be shipped, special care must be taken in labeling and packing. In local contests the contestants usually bring in their own samples, properly iced, but when shipping is neces- sary great care should be taken to pack the samples so that they will remain cold and there will be no breakage. One method is to place the samples in a small, close-fitting container, which, in turn, is securely fastened in an insulated box containing cracked ice. The outer box may be insulated with cork or sawdust. The owner’s name and address should be plainly written on the inside of the cover of the outer box. The package must be plainly addressed on the outside to the consignee and bear the sender’s name and address.

HANDLING SAMPLES AT DESTINATION.

As soon as received at the place where the contest is to be held the sample should be put into cold storage at a temperature between 35° and 40° F. until ready for examination. When the shipping

122545°—19——2

10 Department Circular 53, U. S. Dept. of Agriculture.

boxes are opened the name and address of the consignee (producer) are taken and each of the bottles tagged with its class and number. The name of the contestant, the class of the product, and the number given are placed in an envelope and the envelope sealed. On the outside of this sealed envelope the number of the sample and the class are placed. The person in charge of the contest should keep the records, and it is desirable for the judges to SENG the samples only by numbers.

As there are four bottles in each entry one may be used for chem- ical analysis; one for bacteriological examination and sediment; one for judging flavor, odor, and appearance; and one held in reserve to be placed on exhibition, This method may be varied to meet special conditions,

The best sample in each class must be declared the winner of that class, provided, of course, that all conditions have been complied with. In case of ties in the total score, the entry having the lowest bacteria count should outrank the others. Samples of high merit that have not won a prize may be awarded a diploma or cerfificate bearing the seal of the health department. The following form may

be used: DIPLOMA OF MERIT.

The Health Department

Of the: Cityot f.5)12 522 .se-eesecteeee = Awards a Diploma of Merit to

Fora sample of ......--..------ Bee haater ye SCOLING foie ccin eestor ee na sae , exhibit a the). ie ceee somes tea SSE moe tere weal bie tele held Abo. cccicc sieleeisis ove s oe eee Judges

(Signed): - s...cs. tede eek 5 eee eee

[SEAL.] Superintendent of Contest.

The persons in charge of the contest should furnish contestants with detailed copies of their scores, and be ready to answer questions regarding them. As the principal reason for holding the contests is to improve the milk supply, authorities should take advantage of the data furnished by dairymen to point out faults in the production and handling of the milk or cream and advise ways to improve the quality.

CONTESTS IN WHICH SAMPLES ARE TAKEN ON THE STREET. This method of conducting milk contests, if properly carried out, furnishes a basis for grading the milk supply of cities. As in the

contests with prepared samples, the three classes—pasteurized and raw market milk and cream and certified milk—must be kept separate.

Milk and Cream Contests. 11

COLLECTING THE SAMPLES.

At least once a month, and oftener if possible, the health depart- ment should collect 2 pint bottles of milk and 2 half-pint bottles of cream from each person delivering milk or cream in the city. At the time of collection one of the samples should be well mixed, the bottle opened, and the temperature of the milk or cream taken. This sample should be properly marked so as not to be used for bacterio- logical examination, but used later for chemical determinations. Both samples should be placed immediately in ice until ready for analysis. The following determinations are made: Bacteria, sedi- ment, specific gravity, fat, solids not fat, flavor and odor, and con- dition of bottle and cap.

Careful records of the determinations as well as the temperature of the milk or cream at time of collection should be made and prop- erly filed.

FILE CARD FOR RECORDING MILK SCORES.

TWN GG Uy a Clseses aes boats seeeeee eee INaSMeOMOWNEN =... 222-5 2.0-5-c- 5 cee Bs cya Rohn ate ciated c wid anes er ee ee DIR@Ocotske HERES Dp eae P. O. address ..... FE Pees ene oe Tem- e- pera- | Bott) Date jria per! yy Sedi- | Specific ture bea . avor and odor . Solids and sample| cubic ment | gravity on Remarks. taken. | centi- | Score and remarks. score. | at 60° Fat. | not fat. street en meter. F. De sae grees

we eee ccccccccccee

After a definite period of time—for example, 3, 6, or 12 months— the determinations made on the samples of each dairyman are aver- aged; these averages constitute a new record which is transferred to the milk or cream card and scored. The scores allowed each point are added together to make the total score. At the end of the period the names of the dairymen are published in the order of their scores, the highest in each class coming first.

For the purpose of grading, the dairymen of each class scoring above 90 may be put in the same grade; those scoring between 80 and 90 in another grade; and those scoring below 80 in another, thus making three grades in each class.

LABORATORY EQUIPMENT FOR CONDUCTING CONTESTS.

It is evident that the health department of a city must have proper laboratory equipment in order to conduct milk and cream contests. The following is a guide for the equipment of an average laboratory for doing such work. Quantities of the supplies may be varied according to the amount of work to be done.

12 Department Circular 53, U. S. Dept. of Agriculture.

CHEMICAL EQUIPMENT.

Babcock milk tester, 8 to 24 bottles, for fat determinations.

Westphal balance or accurate lactometer with cylinder for specific gravity deter- mination.

Milk-test bottles, 8 per cent, for fat in milk.

Cream-test bottles, 9 grams, 50 per cent, for fat in cream.

Cream-test scales for weighing cream.

Pair dividers.

Pipettes, 17.6 cubic centimeters, for measuring milk or acid.

Combined acid bottle and pipette.

Burette, 50 cubic centimeters, glass stopcock, graduated in tenths, for acidity deter- mination.

Glass stirring rods for acidity determination.

Burette holder.

Beakers, 100 cubic centimeters, for flavor and odor and acidity.

Sediment tester for dirt in milk.

Cotton disks for sediment.

Fahrenheit dairy thermometers for temperature of samples on collection.

Bunsen burners, gas, with rubber tubing.

Commercial sulphuric acid for fat determination.

Sodium hydroxid, tenth-normal solution, for acidity.

Phenolphthalein indicator for acidity determination.

BACTERIOLOGICAL EQUIPMENT.

Autoclay, medium size, for steam sterilization. Sterilizing oven for dry-air sterilization. Incubator, for growing bacterila. Water bath for melting agar tubes. Por preparation of media: 3alance, with weights to 5 kilos. Double boiler, one-half gallon. Funnel glass, 6 inches in diameter. Burette, 50 cubic centimeters, glass stopcock, graduated in tenths. Gas stove, single burner. l-cubic centimeter pipettes to deliver between 2 marks, graduated in tenths with extra tenth above 0 mark, for measuring dilutions. Test tubes, lipless, for holding 10 cubic centimeters media. Test-tube baskets. For measuring liquids: 5 cubic centimeter pipette. 10 cubic centimeter pipette. 25 cubic centimeter pipette. 50 cubic centimeter pipette. 100 cubic centimeter cylinder, graduated. 500 cubic centimeter cylinder, graduated. 1,000 cubic centimeter cylinder, graduated. Petri dishes for plating samples. Glass bottles, 8-ounce, for sterile dilution water. Thermometer (—10° to +110° ©.) for temperatures in laboratory operations. Thermometer (—10° to +200° C.) for dry-air ovens. Pipette boxes, copper or galvanized iron, for holding 1-cubic centimeter pipettes.

Milk and Cream Contests. 13

For counting bacteria: Reading glass, 4-inch, 2} magnifications. Counting plate. Tally machine. Wax pencil. Absorbent cotton for filtering media. Nonabsorbent cotton for plugging test tubes. Canton flannel for filtering media. For making media: Peptone; beef extract; agar, shredded. For adjusting media: Sodium hydroxid, normal. Sodium hydroxid, tenth normal. Hydrochloric acid, tenth normal. Phenolphthalein indicator.

METHODS OF ANALYZING AND TESTING.

It is of special importance in all analytical work that the standard methods prescribed be followed. No attempt is made here to give details of milk analysis, as every laboratory equipped to do this kind

Fig. 1.—Westphal balance and lactometer for determining specifie gravity of milk.

of work must certainly contain the proper reference books. Besides the usual books found in all health or food laboratories the analyst should have the following pamphlets:

Chemical Testing of Milk and Cream, Bureau of Animal Industry, Leaflet A 12, U.S. Department of Agriculture, Washington, D. ©.

Official and Provisional Methods of Analysis, Association of Official Agricultural Chemists, Bureau of Chemistry Bulletin 107, Revised, U. S. Department of Agricul- ture, Washington, D. ©.

Testing Milk and Cream for Butterfat, Circular 78, Purdue University Agricultural Experiment Station, La Fayette, Ind.

14 Department Circular 53, U. S. Dept. of Agriculture.

Standard Methods of Bacteriological Analysis of Milk, Provisional Report of the Laboratory Section of the American Public Health Association, 126 Massachusetts

Avenue, Boston, Mass. SPECIFIC GRAVITY.

The determination of specific gravity should be made either by a Westphal balance or by an accurately graduated lactometer. (Fig. 1.) The importance of accuracy in taking the specific gravity is better un- derstood when it is realized that from the specific gravity and the fat found, the total solids or solids not fat are calculated. As most of the lactometers are standardized to 60° F. (15° C.), it is important that the temperature of the milk to be tested should closely approxi- mate this temperature. If it is necessary to take the readings at some other temperature, the following table of correction, by Dr. Paul Vieth, should be used.

Table for correcting the specified gravity of milk according to temperature.

Degrees of thermometer (Fahrenheit).

Degrees of lac- tometer.

19.0 | 19.0 | 19.1 | 19.1 | 19.2} 19.2 | 19.3 | 19.4 | 19.4 | 19.5 | 19.6 | 19.7} 19.8) 19.9] 19.9)..... 19.9 | 20.0 | 20.0 | 20.1 | 20.2 | 20.3 | 20.3 | 20.3 | 20.4 | 20.5 | 20.6 | 20.7 | 20.8 | 20.9 | 20.9|]...-. 20.9 | 21.0] 21.0 | 21.1} 21.2 | 21.2 | 21.3 | 21.3 | 21.4 | 21.5 | 21.6 | 21.7 | 21.8 | 21.9] 21.9|..... 21.9 | 22.0 | 22.0 | 22.1] 22.2 | 22.2 | 22.3 | 22.3 | 22.4 | 22.5 | 22.6 | 22.7 | 22.8 | 22.8] 22.9)..... 22.9 | 22.9 | 23.0} 23.1} 23.2 | 23.2 | 23.3 | 23.3 | 23.4 | 23.5 | 23.6 | 23.6 | 23.7 | 23.8 | 23.9 |..... 23.8 | 23.9 | 24.0 | 24.0} 24.1 | 24.1 | 24.2 | 24.3 | 24.4 | 24.5 | 24.6 | 24.6 | 24.7 | 24.8 | 24.9]_.... 24.8 | 24.9 | 24.9 | 25.0] 25.1 | 25.1 | 25.2 | 25.2 | 25.3 | 25.4 | 25.5 | 25.6 | 25.7 | 25.8] 25.9]..... 25.8 | 25.9 | 25.9 | 26.0] 26.1 | 26.1 | 26.2 | 26.2 | 26.3 | 26.4 | 26.5 | 26.6 | 26.7 | 26.8] 26.9|.-..- 26.7 | 26.8 | 26.8 | 26.9 | 27.0 | 27.0 | 27.1 | 27.2 | 27.3 | 27.4 | 27.5] 27.6 | 27.7 | 27.8 | 27.9]....- 27.7 | 27.8 | 27.8 | 27.9 | 28.0 | 28.0 | 28.1 | 28.2 | 28.3 | 28.4 | 28.5 | 28.6 | 28.7 | 28.8 | 28.9 )...-- 28.6 | 28.7 | 28.7 | 28.8 | 28.9 | 29.0 | 29.1 | 29.1 | 29.2 | 29.3 | 29.4 | 29.6 | 29.7 | 29.8 | 29.9)..... 29.5 | 29.6 | 29.6 | 29.7 | 29.8 | 29.9 | 30.0 | 30.1 | 30.2 | 30.3 | 30.4 } 30.5 | 30.6 | 30.8 | 30.9 |.-.-- 30.4 | 30.5 | 30.5 | 30.6 | 30.7 | 30.9 | 31.0 | 31.1 | 31.2] 31.3 | 31.4 | 31.5 | 31.6 | 31.7 | 31.9 |.._-- 31.3 | 31.4 | 31.4 | 31.5 | 31.6 | 31.8 | 31.9 | 32.0 | 32.1 | 32.3 | 32.4 | 32.5 | 32.6 | 32.7 | 32.9 |....- 32.2 | 32.3 | 32.3 | 32.4 | 32.5 | 32.7 | 32.9 | 33.0 | 33.1 | 33.2 | 33.3 | 33.5 | 33.6 | 33.7 | 33.9 |--.-- 33.0 | 33.1 | 33.2 | 33.4 | 33.5 | 33.6 | 33.8 | 33.9 | 34.0 | 34.2 | 34.3 | 34.5 | 34.6 | 34.7 | 34.9 ]...--

20 ee Seance eae eee 20.1) 20.2 | 20.2 | 20.3 | 20.4 | 20.5 | 20.6 | 20.7 | 20.9 | 21.0 | 21.1] 21.2) 21.3 | 21.5] 21.6 DU aetcaa tice oe ae teeee 21.1 | 21.2 | 21.3 | 21.4 | 21.5 | 21.6 | 21.7 | 21.8 | 22.0 | 22.1 | 22.2 | 22.3 | 22.4 | 22.5] 22.6 Diora eta se Sieiais oiniaele Se ee 22.1 | 22.2 | 22.3 | 22.4 | 22.5 | 22.6 | 22.7 | 22.8 | 23.0 | 23.1 | 23.2 | 23.3 | 23.4 | 23.5] 23.7 QBise cess dete sceceenesss 23.1 | 23.2 | 23.3 | 23.4 | 23.5 | 23.6 | 23.7 | 23.8 | 24.0} 24.1 | 24.2 | 24.3 | 24.4 | 24.6] 24.7. ere ase senisecceenscee 24.1 | 24.2 | 24.3 | 24.4 | 24.5 | 24.6 | 24.7 | 24.9 | 25.0] 25.1 | 25.2] 25.3 | 25.5] 25.6| 25.7 7A ele SABE OSA AERO Ce 25.1 | 25.2 | 25.3 | 25.4 | 25.5 | 25.6 | 25.7 | 25.9 | 26.0] 26.1 | 26.2] 26.4] 26.5 | 26.6] 26.8 QB sais sieiawaisienisiceec eas 26.1 | 26.2 | 26.3 | 26.5 | 26.6 | 26.7 | 26.8 | 27.0 | 27.1) 27.2 | 27.3 | 27.4 | 27.5] 27.7] 27.8 Ap assisisice seas cesee Tes 27.1 | 27.3 | 27.4 | 27.5 | 27.6 | 27.7 | 27.8 | 28.0 | 28.1] 28.2 | 28.3 | 28.4 | 28.6] 28.7] 28.9 Doce s siou.c1s cowie emiae esc 28.1 | 28.3 | 28.4 | 28.5 | 28.6 | 28.7 | 28.8 | 29.0 | 29.1 | 29.2 | 29.4] 29.5} 29.7 | 29.8] 29.9 COs Sema ficeases ceases 29.1 | 29.3 | 29.4 | 29.5 | 29.6 | 29.8 | 29.9 | 30.1 | 30.2 | 30.3 | 30.4 | 30.5 | 30.7 | 30.9] 31.0 BO meses antec esce 30.1 | 30.3 | 30.4 | 30.5 | 30.7 | 30.8 | 30.9 | 31.1 | 31.2 | 31.3 | 31.5 | 31.6 | 31.8] 31.9] 32.1 Si bes Sia AOR Se ae eer 31.2] 31.3 | 31.4 | 31.5 | 31.7 | 31.7 | 31.8 | 32.0) 32.2 | 32.4 | 32.5 | 32.6 | 32.8 | 33.0] 33.1 S15 ae oe eee nen 32.2 | 32.3 | 32.5 | 32.6 | 32.7 | 32.9 | 33.0 | 33.2 | 33.3 | 33.4 | 33.6 | 33.7] 33.9] 34.0] 34.2 Oo maser eens Sane 33.2 | 33.3 | 33.5 | 33.6 | 33.8 | 33.9 | 34.0 | 34.2 | 34.3 | 34.5 | 34.6 | 34.7] 34.9] 35.1] 35.2 Oe arene te elava: <i icveia: are 34.2 | 34.3 | 34.5 | 34.6 | 34.8 | 34.9 | 35.0] 35.2 | 35.3 | 35.5 | 35.6 | 35.8 | 36.0] 36.1] 36.3 DOnEeee asec sacst ce 35.2 | 35.3 | 35.5 | 35.6 | 35.8 | 35.9 | 36.1 | 36.2} 36.4 | 36.5 | 36.7 | 36.8 | 37.0 | 37.2] 37.3

The milk to be tested for specific gravity should be well mixed either by gently inverting the bottle several times or by pouring back and forth from the bottle to a beaker. In mixing the milk, as

>on

an

Oe ad

Milk and Cream Contests. 15

well as in pouring into a cylinder for the determination of the specific gravity, care should be taken to avoid the formation of air bubbles.

In using the lactometer a meniscus is formed at the point where the stem comes in contact with the milk. The point to be read is at the actual surface of the liquid and not at the top of the meniscus,

MILKFAT (BUTTERFAT).

In order to distribute the fat evenly the bottle of milk or cream must be well mixed, preferably by pouring back and forth from the bottle to a beaker. This should be done just before the product for analysis is measured out. The charge of milk consists of 17.6 cubic centimeters and is measured; the cream charge consists of 9 or 18 grams and is always weighed.

MILK. CREAM.

Fic. 2.—Method of reading Babcock test bottles. In reading fat column in milk testing, read from atob,notatoc,noratod. Incream testing, read from a toc, not a tod, nor a to d.

The Babcock tester must be run at a definite speed, depending upon the diameter of the centrifuge. The proper speed is usually indicated on the machine and runs about as follows: 1,000 revolu- tions a minute for 12-inch testers, and 800 revolutions for 18-inch testers. The samples should be run three times for 5, 2, and 1 minute periods, respectively. Hot water is added to bring the solu- tion up to the neck of the bottle after the 5-minute period.

The fat column should be clear, with a yellow or light-yellow color. If the fat column contains white flakes (the result of too weak or too little acid) or black flakes (the result of too strong or too much acid), the test must be repeated. ‘Before the reading is taken the bottles with their columns of fat must be placed in water approximating 140° F. (60° C.), so that the fat column is surrounded

16 Department Circular 53, U. S. Dept. of Agriculture.

by the hot water. They should remain in the bath about 10 minutes and be read, one by one, immediately on removal. In measuring the fat column in the milk test, read from the bottom to the extreme top of the meniscus. In measuring the fat column in the cream test, read from the bottom to the lower part of the meniscus. How- ever, in the case of cream a more accurate reading can be obtained by adding a few drops of glymol to the cream test bottle on removal from the water bath. This flattens the meniscus and makes read-

ing easier. ~ SOLIDS NOT FAT.

The solids not fat may be determined by the formula S. N. F.=

1 1,.+.2F, in which ‘‘L” stands for the third and the fourth figures of the specific gravity and ‘‘F” stands for the percentage of fat.

/

Example: Specific gravity at 60° F., 1.032; fat, 4 per cent. 3740.2X4=8.80 solids not fat.

The following table may be used for estimating the solids not fat:

Table for determining the solids not fat in milk from any given specific gravity and per cent

of fat. Lactometer reading at 60° F. (Quevenne degrees). Per cent of fat 26 | 27 | 28 29 30 31 | 32 33 34 35 36 | | 2.00 6. 90 @5 7.40 7.65 7.90 8.15 8. 40 8. 66 8.91 . 9.16 9. 41 2.05 6. 91 7.16 7.41 7. 66 7.91 8. 16 8. 41 8. 67 8. 92 9.17 9. 42 2.10 6. 92 Voure 7.42 7. 67 7. 92 8.17 8. 42 8. 68 8. 93 9.18 9. 43 2.15 6. 93 7.18 7.43 7.68 7. 93 8.18 8. 43 8. 69 8. 94 9. 19 9. 44 2. 20 6. 94 7.19 7.44 7. 69 7. 94 8.19 8. 44 8.70 8.95 9. 20 9. 45 Dee 6.95 7. 20 7. 45 7.70 7.95 8. 20 8.45 8.71 8. 96 9. 21 9. 46 2. 30 6. 96 (EPA 7. 46 est 7. 96 8. 21 8. 46 8. 72 8. 97 9. 22 9. 47 2.35 6.97 7. 22 7.47 Weihe 7.97 8. 22 8. 47 8.73 8.98 9. 23 9. 48 2. 40 6.98 7.23 7.48 (AYE 7.98 8. 23 8. 48 8.74 8.99 9. 24 9. 49 2.45 6.99 7. 24 7.49 7. 74 7.99 8. 24 8. 49 8.75 9. 00 9. 25 9. 50 2. 50 7.00 sien 7. 50 tald 8. 00 8. 25 8. 50 8. 76 9. 01 9. 26 9.51 280) 7.01 7. 26 COL 7.76 8. 01 8. 26 8. 51 8.77 9. 02 9. 27 9. 52 2. 60 7. 02 Chea 7. 52 CEES 8. 02 8. 27 8. De) asc 9. 03 9. 28 9. 53 2. 65 7.03 7. 28 Tso 7.78 8. 03 8. 28 8. 53 8.7 9. 04 9. 29 9. 54 VBA 7. 04 7.29 7. 54 7.79 8. 04 8. 29 8. 54 8. 80 9. 05 9. 30 9. 55 2.75 7. 05 7.30 (65) 7. 80 8. 05 8. 30 8. 56 8. 81 9. 06 9. 31 9. 56 2. 80 7. 06 (cil 7. 56 7. 81 8. 06 8.31 8. 57 8. 82 9. 07 9. 32 9. 57 2. 85 7.07 7.32 Te5e 7. 82 8. 07 8.32 8. 58 8. 83 9. 08 9. 33 9. 58 2. 90 7.08 7.33 7. 58 7.83 8. 08 8.33 8. 59 8. 84 9. 09 9.34 9. 59 2.95 7.09 7.34 7.59 7. 84 8.09 8.35 8. 60 8. 85 9.10 9.35 9. 60 3. 00 7.10 7.35 7.60 7.85: 8.10 8.36 8. 61 8. 86 9.11 9.36 9. 61 3. 05 7.11 7.36 7.61 7. 86 8.12 8. 37 8. 62 8. 87 9.12 9. 37 9. 63 3.10 7.12 4.30 7. 62 7. 87 8.13 8.38 8. 63 8. 88 9.13 9.38 9. 64 3.15 7.13 7.38 7. 63 7. 88 8. 14 8.39 8. 64 8. 89 9.14 9. 40 9. 65 3. 20 7.14 7.39 7. 64 7. 89 8.15 8. 40 8. 65 8. 90 9.15 9. 41 9. 66 3. 25 Wold 7.40 7. 65 7.91 8.16 8. 41 8. 66 8.91 9.17 9. 42 9. 67 3.30 7.16 7.41 7. 66 7.92 8.17 8. 42 8. 67 8. 92 9.18 9. 43 9. 68 3.35 7.17 7.42 7. 68 7.93 8.18 8. 43 8. 68 8.93 9.19 9. 44 9. 69 3. 40 7.18 7.43 7. 69 7.94 8.19 8. 44 8. 69 8. 94 9. 20 9. 45 9.70 3. 45 7.19 7.44 7.70 7.95 8. 20 8. 45 8.70 8.95 9. 21 9. 46 9.71 3. 50 7. 20 7.45 7.71 7. 96 8. 21 8. 46 8.71 8. 96 9. 22 9. 47 9.72 3. 55 7.21 7.47 W12 7.97 8. 22 8.47 8. 72 8.97 9. 23 9. 48 9. 73 3. 60 eine 7. 48 toto 7.98 8. 23 8. 48 8.73 8.98 9. 24 9. 49 9. 74 3. 65 7. 23 7.49 7. 74 7.99 8. 24 8. 49 8. 74 8.99 9. 25 9. 50 9.75 3.7 7.24 7. 50 ase 8. 00 8. 25 8. 50 8.75 9. 00 9. 26 9. 51 9. 76 SH dee 7. 51 7.76 8. OL 8. 26 8.51 8. 76 9. 01 9. 27 9. 52 9.77 3. 80 7. 26 7. 52 (BU 8. 02 8. 27 8. 52 8.77 9. 02 9. 28 9. 53 9.78 3. 85 (BPLh 7. 53 7.78 8. 03 8. 28 8.53 8. 78 9. 03 9. 29 9. 54 9.79 3.90 7. 28 7. 54 (er) &. 04 8. 29 8. 54 8.79 9. 04 9. 30 9. 55 9. 80 3.95 7. 29 7. 55 7. 80 8. 05 8. 30 8.55 &. 80 9.05 shail 9. 56 9. 82

Milk and Cream Contests. ee

Table for determining the solids not fat in milk from any given specific gravity and per cent of fat—Continued.

Lactometer reading at 60° F, (Quevenne degrees).

Per cent 1 ee = of fat | 26 27 28 29 30 31 32 33 34 35 36 4.00 7.30 7. 56 7. 81 8.06 8.31 8.56 | 8.81 | 9.06 9.32 9. 57 9.83 4.05 4.31 7.57 7. 82 8. 07 8. 32 8. 57 8. 82 9. 07 9. 33 9. 58 9. 84 4.10 7.32 7.58 7.83 8. 08 8.33 8. 58 8. 83 9. 08 9. 34 9.59 9.85 4.15 wae 7.59 7. 84 8. 09 8.34 8.59 8. 84 9.10 9.35 9. 61 9.86 4. 20 7.34 7.60 7.85 8.10 8.35 8. 60 8. 85 9.11 9. 36 9. 62 9. 87 4.25 1280 7.61 786° | S11 8.36 8.61 8.87 9.12 9.37 9. 63 9.88 4.30 7.36 7.62 7.87 8.12 8.37 8. 62 Sag8 9.13 9. 38 9. 64 9.89 4.35 0.388 7.63 7. 88 8.13 8.38 8. 63 8.89 9.14 9. 39 9. 65 9. 90 4.40 7.38 7. 64 7.89 8.14 8.39 8. 64 8.90 9.15 9.40 9. 66 9.91 4.45 7.39 7.65 7.90 8.15 8. 40 8.65 8.91 9.16 9.41 9.67 9. 92 4.50 7.40 7. 66 7.91 8.16 8.41 8. 66 8. 92 9.17 9.42 9.68 9.93 4.55 7.42 Veuiye 7.92 8. 17@ 8.42 8. 67 8. 93 9.18 9. 43 9. 69 9. 94 4.60 7.43 7.68 7.93 8.18 8. 43 8. 68 8. 94 9.19 9.40 | 9.7 9.95 4.65 7.44 7.69 7.94 8.19 8. 44 8. 69 8. 95 9. 20 9.45 9.71 9.96 4.70 7.45 7.70 7.95 8. 20 8.45 8.70 8. 96 9.21 9.46 9.72 9.97 4.75 7.46 eid 7.96 8. 21 8.46 8. 71 8.97 9. 22 9.47 9. 73 9.98 4.80 7.47 ante 7.97 8. 22 8.47 8.72 8. 98 9. 23 9.48 9. 74 9.99 4.85 7.48 Maiko 7.98 8. 23 8.48 8. 73 8.99 9. 24 9.49 9.75 10. 00 4.90 7.49 7.74 7.99 8. 24 8. 49 8. 74 9.00 9. 25 9. 50 9.76 10. 01 4.95 7.50 7.75 8.00 8. 25 8. 50 8.75 9.01 9.26 9.51 9.77 10. 02 5.00 7.51 7.76 8.01 8. 26 8. 51 8.76 9.02 9.27 9. 52 9.78 10. 03 5.05 7. 52 ead, 8. 02 8. 27 8. 52 8. 78 9.03 9. 28 9.53 9.79 10. 04 5.10 7.53 7.78 8. 03 8. 28 8..53 8.79 9. 04 9.29 9, 54 9.80 10. 05 5.15 7. 54 ek) 8.04 8. 29 8.54 8. 80 9.05 9.30 9. 55 9.81 10. 06 5. 20 7.55 7.80 8.05 8. 30 8. 55 8.81 9.06 9.31 9.56 9. 82 10. 07 5.25 7. 56 7.81 8. 06 8.31 8. 56 8. 82 9.07 9. 32 9. 57 9.83 10. 08 5.30 hae 7. 82 8. 07 8. 32 8.57 8.83 9.08 9. 33 9.58 9. 84 10.09 5.35 7. 58 7.83 8. 08 Sad 8. 58 8. 84 9.09 9.35 9. 60 9.85 10.10 5.40 709 7. 84 8.09 8.34 8. 60 8.85 9.10 9. 36 9. 61 9.86 10.11 5.45 7.60 7.85 8.10 8.35 8. 61 8. 86 goli: 9.37 9. 62 9.87 10.12 5. 50 7.61 7.86 8.11 8.36 8. 62 8. 87 ON12 9.38 9. 63 9.88 10.13 5. 55 7.62 7.87 8.12 8. 38 8. 63 8. 88 9.14 9.39 9. 64 9.89 10. 14 5. 60 7.63 7.88 8.13 8.39 8. 64 8.89 9.15 9. 40 9. 65 9. 90 10.15 5. 65 7.64 7.89 8.14 8. 40 8. 65 8. 90 9.16 9. 41 9. 66 9. 91 10. 16 5.70 7.65 7.90 8.15 8.41 8. 66 8.91 9.17 9. 42 9. 67 9. 92 10.17 §.15 7.66 7.91 8.16 8. 42 8. 67 8. 93 9.18 9. 43 9. 68 9. 93 10.18 5. 80 7. 67 7. 92 8.17 8. 43 8. 68 8. 94 9.19 9. 44 9. 69 9. 94 10.19 5.85 7.68 7.93 8.19 8. 44 8. 69 8.95 9. 20 9.45 9.70 9.95 10. 21 5. 90 7.69 7.94 8. 20 8.45 8.70 8.96 9. 21 9. 46 9.71 9. 96 10. 22 5.95 7.70 7.95 8. 21 8. 46 8.71 8.97 9, 22 9.47 9.72 9.97 10. 23 6.00 Wadd 7.96 8. 22 8.47 8.72 8.98 9. 23 9.48 9.73 9.98 10. 24 6.05 7.72 7.97 8. 23 8. 48 8.73 8.99 9. 24 9.49 9. 74 9.99 10. 25 6.10 1.43 7.98 8. 24 8.49 8. 74 9. 00 9. 25 9. 50 9.75 10. 00 10. 26 6.15 7.74 7.99 8. 25 8. 50 8.75 9. 01 9. 26 9.51 fF 9.76 10. O1 10. 27 6. 20 7.95 8. 00 8. 26 8. 51 8.76 9. 02 9. 27 9.52 | 9.77 10. 02 10. 28 6. 25 7.76 8. 01 8.27 8. 52 8.77 9. 03 9. 28 9.53 | 9.78 10. 03 10. 29 6.30 7.77 8. 02 8. 28 8. 53 8.78 9. 04 9. 29 9. 54 9.79 10. 04 10. 30 6.35 7.78 8. 03 8. 29 8. 55 8. 79 9.05 9.30 9. 55 9. 80 10.05 10. 31 6. 40 7.79 8. 04 8. 30 8. 56 8. 80 9. 06 9.31 9.56 | 9.81 10. 06 10. 32 6.45 7.80 8.05 8.31 8.57 8.81 9.07 9.32 bo GY fe Weak! ats 10. 07 10. 33 6. 50 7.81 8. 06 8. 32 8. 58 8. 82 9.08 9.33 9.58 | 9.83 10. 08 10. 34 6.55 7.82 8.07 $233, 8.59 8.83 9.09 9. 34 9. 59 9.84 | 10.09 10. 35 6. 60 7.83 8. 08 8. 34 8. 60 8. 84 9.10 9.35 9. 60 9.85 10.10 10. 36 6. 65 7.84 8.09 8.35 8. 61 8.85 9.11 9. 36 9. 61 9.86 10. 11 10. 37 6.70 7.85 8.10 8.36 8. 62 8. 86 9.12 9.37 9. 62 9.87 10. 12 10. 38 6.75 7. 86 8: 11 ERY s 8. 63 8. 87 9.13 9.38 9. 63 9. 88 10. 13 10. 39 6. 80 7.87 8.12 8. 38 8. 64 8. 88 9.14 9.39 9. 64 9.89 10. 14 10. 40 6.85 7. 88 8.13 8.39 8.65 8. 89 9.15 9. 40 9.65 9.90 10.15 10. 41 6.90 7.89 8.14 8. 40 8. 66 8. 90 9.16 9. 41 9. 66 9.91 10. 16 10. 42 6.95 7.90 8.15 8.41 8. 67 8. 91 9.17 9. 42 9. 67 9. 92 10.17 10. 43

PROPORTIONAL PARTS. nn eee EEE EEEE ESSE SST GASSES SEES

Fraction to be ; : Fraction to be P Fraction to be Lactometer | aqded to solids || Tactometer | sqded to solids Lactometer | added to solids fraction. not fat. TBeuONs not fat. at a not fat. ms : |) - 7 0.1 0. 03 | 0.4 0.10 0.7 0.18 .2 05 5 e193 ‘8 -20 3 | -08 .6 15 19 123

pe a

18 Department Circular 53, U. S. Dept. of Agriculture.

Directions for using the table.-—If the specific gravity as expressed in Quevenne degrees is a whole number, the per cent of solids not fat is found at the intersection of the vertical column headed by this number, with the horizontal column corresponding to the per cent of fat. If the specific gravity as expressed in Quevenne degrees is a whole number and a decimal, the per cent of solids not fat corre- sponding to the whole number is first found, and to that is added the fraction found opposite the tenth under ‘‘ Proportional parts.” Two examples may suffice for illustration: (1) Fat, 3.8 per cent; specific gravity, 1.0320. Under column headed 32, 8.77 per cent is found corresponding to 3.8 per cent fat. (2) Fat, 3.8 per cent; specific gravity, 1.0325. The per cent of solids not fat corresponding

Fig. 3.—Determination of acidity.

to this per cent of fat and a specific gravity of 32 is 8.77. Under ‘Proportional parts” the fraction appearing opposite 0.5 is 0.13, which, added to 8.77, makes 8.90, the desired per cent.

ACIDITY.

In order to obtain comparable results, it is best to follow strictly the method given in leaflet A 12, previously mentioned. The milk must not be diluted with water, as that causes a perceptible error in the results. Fifty cubic centimeters of milk or cream are taken and titrated against a tenth-normal sodium-hydroxid solution, using phenolphthalein as indicator. Care must be taken near the end of

Milk and Cream Contests. 19

the titration in order to develop a faint pink color over the entire surface of the milk. The pink color disappears on standing for a short time. The calculation is as follows:

ce NaOH n/10 x .009 x 100

Per cent of acidity= 0 vo

The following table gives the acidity when 50 cubic centimeters of milk are titrated against tenth-normal alkali:

Determination of acidity in milk,

Cubie cen- Per cent Cubic cen- Per cent Cubic cen- Percent || Cubic cen- Per cent

timeters acidity as timeters acidity as || timeters acidity as timeters acidity as NaOH n/10.} lactic acid. || NaOH n/10.| lactic acid. | NaOH n/10.| lactic acid. |)/NaOH. n/10. lactic acid.

4.0 0. 072 7.5 0.135 11.0 0.198 14.5 0. 261

4.5 - 081 8.0 . 144 11.5 . 207 15.0 - 270

5.0 . 090 8.5 <153 12.0 . 216 15.5 279

5.5 .099 9.0 . 162 1255 225 16.0 . 288

6.0 . 108 9.5 palal 13.0 . 234 16.5 . 297

6.5 -117 10.0 . 180 13.5 . 243 17.0 -306

7.0 . 126 10.5 . 189 14.0 . 252 17.5 ~315

SEDIMENT.

The sediment in milk may be determined by means of some form of sediment tester or by observing the bottom of the milk in the bottle. If the sediment tester is used the pint sample of milk should

Fic. 4.—Sediment testers.

be warmed slightly before being run through the tester, since cold milk runs through slowly. At the completion of the test the resulting cotton disks are grouped according to the quantity of sediment shown. A perfectly clean cotton scores 10. Figure 5 shows a method of grouping with numerical rating. While the numbers in the figure show a half-point difference only, the analyst can make ratings be- tween these numbers. For example, a cotton disk showing less dirt than 8, but more than 8.5, can be given a rating between 8 and 8.5.

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Department Circular 53, U. S. Dept. of Agriculture.

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Care must be taken to rinse out the tester after each sample has been run through.

It is inadvisable to use the sediment tester for cream, for on account of its heavy viscosity cream may clog the tester entirely. Particles of fat may also obscure any sediment. Sediment in cream should therefore be judged in the bottle. Before scoring, the bottles should be allowed to stand undisturbed for at least an hour to allow any sediment to settle. Then the bottle should be raised carefully, tip- ping only slightly, so that the bottom can be observed. To score perfect, not so much as a movable speck must be visible in the bottom of the bottle. When sediment is present, points must be deducted according to the quantity.

This bottle method may be used in the same manner for testing the sediment in milk, and the grading shown in figure 5 applies equally in determining the score.

FLAVOR AND ODOR.

The most common “off flavors’? and odors found in milk and cream are those produced by certain feeds; by the absorption of foul odors from the stable; and from the presence of foreign substances in the milk. Before scoring, the samples should be set in warm water to warm the milk and cream slightly. The scoring must be done in a room free from odors. The sample of milk or cream should be well mixed before the cap is removed, then about half the contents of the bottle should be poured into a clean beaker. Any odor present can be detected by placing the nose over the mouth of the bottle, and the flavor is judged by taking a little of the product into the mouth. It is not advisable to swallow the liquid if many samples are to be scored, since it tends to reduce the sensitiveness of taste. If the flavor is very bad it can usually be definitely classified. Points are deducted for flavors resulting from strong feeds, and for cowy, strong, bitter, sour, or other off flavors.

BOTTLE AND CAP.

Regulation milk bottles must be used in milk and cream contests and they should be completely filled so that there will be no churn- ing. Deductions in the score are made for dirty or chipped bottles and for caps which do not cover the lips of the bottles or which do not fit properly in the cap seats. To obtain a perfect score the top of the bottle must be covered with parchment paper, metal foil, or some other cover impervious to water and dust.

TEMPERATURE.

In contests where the samples are taken on the street, the tempera- ture of the milk must be recorded at the time the sample is collected, but the sample used for ascertaining temperature must not be taken

92 Department Circular 53, U. S. Dept. of Agriculture.

for bacterial count. The inspector by previous experiments must determine how long it takes for the mercury in the tube to become stationary and must leave the thermometer bulb in the milk until the mercury has registered the correct temperature. The thermom- eter should be read, of course, while the bulb is in contact with the milk. Only an accurate thermometer must be used, and care must be taken to prevent breaks in the mercury column. Should such breaks occur they can be corrected by grasping the thermometer in the hand, bulb down, and giving it a long outward sweep, or by placing the bulb in hot water until the mercury has united.

BACTERIAL COUNT.

In the determination of bacteria, the standard methods of bacte- riological analysis of milk should be followed. Special care should be taken in the sterilization of glassware and of dilution bottles, and in the preparation of media. Whenever pessible three plates should be made. In a contest with prepared samples, the following plates

Fig. 6.—Bottles with protective coverings.

are recommended; Two of ;4,, and one of yop. In a contest with street samples it is well to vary this somewhat; as, for example, one of zt5, and two of zgoy; or two of zg, and one of yhoo. In the latter case, however, the analyst will know from his own experience just what dilutions to make.

A blank containing media and dilution water should be run side by side with the regular samples. Plates must not be poured until the temperature of the melted media averages between 106° and 113° F. (41° and 45° C.). The plates must be left in the incubator for 48 hours, and the temperature of the incubator should be kept at about 100° F. (37.5° C.). For counting colonies, a counting plate and a reading glass magnifying 24 diameters should be used, and in report- ing the counts the standard methods should be strictly followed.

In cities where the continuous contest is in operation, and where the results are averaged every 3, 6, or 12 months, there will be from 4 to 24 bacterial counts to average. It is generally conceded that the arithmetical average may give results which are too high, especially

Milk and Cream Contests. 20

when one of the counts is much higher than the others. On that ac- count the following table of per cent ratings has been prepared, the use of which, it is thought, will give a fair average of bacteria in counts of 4 or more. Briefly, the method consists in arranging the ratings and not the bacterial counts, and is more fully explained by an example following the table:

Per cent ratings for various bacterial counts.

Bacteria per | Bacteria per Bacteria per Bacteria per ~ cubic Rating. cubic Rating. || cubie | Rating. cubic Rating. centimeter. centimeter. | centimeter. centimeter. | Per cent. Per cent. | | Per cent. Per cent. 0 100.0 28,000 76.3 66. 000 63.4 140, 000 47.0 500 99.0 29,000 75.9 67, 000 63.1 150, 000 45.1 1,000 97.2 30,000 one 68, 000 62.9 160, 000 43.3 1,500 96.0 31, 000 oe 69, 000 62.6 170, 000 41.5 2,000 94.6 32, 000 74.6 70, 000 62.4 180, 000 39.8 2,500 93.8 33, 000 74.2 71, 000 62.1 190, 000 38.2 3,000 93.0 34, 000 73.9 72,000 61.9 200, 000 36.6 3,500 92.2 35,000 * aso 73, 000 61.6 210, 000 35-1 4,000 91.2 36, 000 (fyal 74, 000 61,4 220, 000 33.6 4,500 90.8 37,000 72.8 75, 000 61.1 230, 000 32.1 5, 000 90.2 38,000 72.4 76, 000 60.8 240, 000 30.6 5,500 89.6 39, 000 72.0 77,000 60.6 250, 000 29.2 6,000 89.0 40, 000 71.6 78, 000 60.3 260, 000 27.8 6,500 88.6 41, 000 71.3 79, 000 60.0 270, 000 26.5 7,000 88.2 42,000 70.9 80, 000 59.8 280, 000 25.2 7,500 87.6 43,000 70.6 81, 000 59.6 290, 000 23.8 8,000 87.2 44,000 70.2 82,000 59.3 300, 000 22.4 8,500 86.8 45,000 69.9 83, 000 59.1 310, 000 2182 9,000 86.4 46,000 69.6 84, 000 58.8 320, 000 20.0 9,500 86.0 47,000 69.2 85, 000 58.6 330, 000 18.8 10,000 85.6 48, 000 68.9 86, 000 58.3 340, 000 17.4 11,000 85.0 49, 000 68.6 87, 000 58.1 350, 000 16.2 12,000 84.4 50, 000 68.3 88, 000 57.8 360, 000 15.0 13, 000 83.8 51, 000 68.0 89, 000 57.6 370, 000 13.8 14, 000 83.2 52,000 67.6 90, 000 57.4 380, 000 12.6 15,000 82.6 53, 000 67.3 91, 000 57.2 390, 000 1S 16, 000 82.0 54, 000 67.0 92, 000 56.9 400, 000 10.4 17,000 81.4 55, 000 66.7 93, 000 56.7 410, 000 9.4 18, 000 81.0 56, 000 66.3 94, 000 56.4 420, 000 8.2 19, 000 80.4 57,000 66.0 95, 000 56.2 430, 000 2 20, 000 80.0 58, 000 65.7 96, 000 56.0 440, 000 6.2 21,000 79.4 59, 000 65. 4 97,000 55.8 450, 000 5.2 22,000 79.0 60, 000 65.2 98, 000 55.6 460, 000 4.0 23, 000 78.6 61,000 64.9 99, 000 55. 4 470, 000 3.0 24, 000 78.2 62, 000 64.6 100, 000 55.1 480, 000 2.0 25,000 77.6 63, 000 64.3 110, 000 53.0 | 490, 000 1.0 26, 000 Mae, 64,000 64.0 120, 000 50.8 500, 000 0.0 27,000 76.8 65, 000 63.7 130, 000 48.8

The bacterial average is determined thus: Suppose the following bacterial counts are the result of five counts from samples taken from dairyman ‘‘A”’: 11,000, 65,000, 80,000, 18,000, 450,000. These are arranged in order with their corresponding per cent ratings taken from the table. The ratings are then added and divided by the number of samples.

Bacteria counts. |Per cent ratings.

11, 000 85.0

65, 000 63.7

80, 000 59.8

18, 000 81.0

450, 000 5.2

))294. 7

58.9

24 Department Circular 53, U. S. Dept. of Agriculture.

The average per cent rating is 58.9. By consulting the table it is found that the rating closest to 58.9 is 58.8; therefore the average bacteria count for samples from A’s dairy is 84,000. By contrast it may be noted that the arithmetical average of the bacterial counts would be 125,000.

PUBLICITY.

Proper publicity has a valuable place in promoting milk and cream contests. It is not only necessary to give newspaper publicity to prepared contests, but the results of all contests should be an- nounced in a popular, readable way. In prepared contests the names of the winners of each class, with their scores and the prizes won, should always be given. In the continuous contest, when the results are announced at definite periods of time, the winners of prizes with their scores may be given. It is thought advisable, however, in con- tinuous contests to group the dairymen in classes, as A, B, and C, and publish these groupings. For instance, all the dairymen scoring between 90 and 100 could be placed in Class A, those scoring between 80 and 90 in Class B, ete.

In connection with the announcement of winners in contests where the samples are taken on the street, it is advisable to arrange a meet- ing of producers to discuss in a practical way methods for producing better milk. Consumers may also be interested, not only in pub- licity but by meetings at which milk questions of interest to them are discussed.

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