an ice cream factory (1917)

8/9/2019 An Ice Cream Factory (1917)

1/104


2/104

Class .^ ^

Bookfopyriglit}!!

Ci)FIRIGHT DEPOSm


3/104


4/104


5/104

An Ice CreamLaboratory Guide

BYW. W. FISK

Assistant Professor of Dairy Industry atCornell University

andH. B. ELLENBERGER

Instructor of Dairy' Industry at Cornell University

NEW YORKORANGE JUDD COMPANY1917


6/104

-^^1f*^

Copyright, 1917, byORANGE JUDD COMPANY

All Rights Reserved

SEP 26 1917If DMd

Printed in U. S. A.

C1.A476258


7/104

TABLE OF CONTENTSPAGEPreface ..... i

Discussion of Laboratory Equipment 3Exercise I

Inspection and Study of Ice Cream Machinery .... 6Discussion of Standardization 8

Exercise IIStandardization 12

Exercise IIITesting Ice Cream for Fat 14

Exercise IVEffect of the Salt and Ice Mixture on Temperature . . 16Classification of Ice Cream 18The Use of Stabilizers 21

Exercise VFreezing Plain Ice Creams 24Exercise VIMethods of Measuring Swell 26

Hardening Ice Cream 28Exercise VII

Freezing Fruit Ice Cream. Hardening in Salt and Ice . 30Exercise VIIIFreezing Nut Ice Cream 32Exercise IX

Freezing Bisque Ice Cream 34Exercise XMaking Bricks and Fancy Moulded Ice Creams . Z7Exercise XI

Freezing Custard Ice Cream 41Exercise XII

Freezing Parfait or French Ice Creams 45Exercise XIII

Freezing Puddings 49Exercise XIV

Freezing Ices . 52ill


8/104

CONTENTSPAGE

Exercise XVFreezing Water Sherbets 54

Exercise XVIFreezing Milk Sherbets 56Exercise XVIIFreezing Punches and Lacto 58

Exercise XVIIIFreezing Mousse 60

Exercise XIXStandardize Mix to a Given Percentage of Fat .... 62Score Card for Judging Ice Cream , . 64

Exercise XXJudging Plain Ice Creams 66

Exercise XXIThe Effect of Fat Content on Ice Cream 68Exercise XXIIThe Effect of Different Binders on Ice Cream .... 70Exercise XXIII

The Effect of Varying Percentages of Milk Solids NotFat on Ice Cream "jo.Exercise XXIV

Freezing Ice Cream from Raw, Pasteurized, Emulsifiedand Homogenized Cream 74Exercise XXVThe Effect of Aging Cream on the Viscosity and Swell . 76Exercise XXVI

The Effect of the Temperature of the Mix as It Enters theFreezer on the Swell 78Exercise XXVII

Effect of the Time of Freezing on the Swell and Qualityof the Ice Cream 80

Exercise XXVIIIBacterial Counts of Ice Cream 82

Exercise XXIXTesting Samples of Gelatin 84

Exercise XXXTrip to Commercial Plants 86

Exercise XXXIStudents' Receipts 88


9/104

PREFACEThe manufacture of ice cream is based on certainscientific principles. It is the purpose of this labora-tory manual to help the student to better understandthe application of these principles. This manual,which is the result of several years' experience inteaching, is not intended as a textbook, but as a briefand concise outline of laboratory exercises. It willalso serve as a suitable place for the student to recordobservations. The exercises have been prepared, sothat each instructor may make selections and combina-tions suitable for the equipment and the needs of hiscourse.

Because this is comparatively a new subject and theideas regarding ice cream production and manufactureare constantly changing, the authors recognize that thismanual will need frequent revisions. An effort willbe made to keep it thoroughly up to date.

Dairy Laboratories,Ncit York State College of Agriculture,

at Cornell University,Ithaca, New York,February, J917.


10/104


11/104

An Ice Cream Laboratory GuideLABORATORY EQUIPMENT

The exercises in this manual may be selected oreasily modified, so that they will be suitable for anylaboratory equipment. For example, the receipts havebeen prepared with the expectation that a 10-gallonfreezer would be used ; if a smaller freezer is used, thereceipts may be reduced proportionally.Much better instruction can be given if the equip-ment includes an artificial refrigerating plant for freez-ing and hardening the ice cream. If the equipmentdoes not include an artificial refrigerating plant, a tuband can freezer, using an ice and salt mixture forfreezing, and a wooden box for packing and hardeningthe ice cream, in ice and salt, may be used. Thehardening box should be made of 2 inch matchedlumber so that it will not leak. The size of the boxwill be determined by the amount of ice cream manu-factured. It should be built in compartments whichwill hold six five gallon cans. This will require a box26 inches wide by 32 inches deep by 36 inches long,outside measurement, with a hinged cover for eachcompartment.

If much ice cream is to be made an ice cream mixeris a necessity, but if a small amount is made each batchmay be mixed in a 40 quart milk can. A homogenizerand emulsor may be included in the equipment.With whatever type of freezer is used, there should

be one or two small hand freezers, to freeze small3


12/104

4 AN ICE CREAM LABORATORY GUIDEbatches and to try new receipts. An ice crusher shouldbe included for crushing ice.The equipment should include the necessary small

utensils, such as pails, dippers, ladles, spoons, ther-mometers, scales, measures, pack cans, etc.There should be a suitable sink connected with hot

and cold water and steam, for washing and scaldingthe utensils. A suitable rack should be provided fordrying and holding the utensils and pack cans. Be-cause of the salt used, care must be exercised, as it isliable to get on the utensils and cause them to rust.All belts and gears on machines should be protected,so that persons cannot be caught and injured in them.


13/104


14/104

AN ICE CREAM LABORATORY GUIDE

EXERCISE NUMBER IINSPECTION AND STUDY OF ICE CREAMMACHINERYArtificial refrigerating systems.

I. State briefly the principles involved in an arti-ficial refrigerating plant.

11. Make drawings showing the working principlesof the refrigerating system.III. Tell how to start and stop the compressor.

Ice cream freezers.I. Tell the principles on which the various types

of freezers work.II. How can the temperature in the different types

of freezers be regulated?Cleaning utensils.

I. How should utensils be washed? Why?II. Are all utensils so constructed that they may be

easily and thoroughly cleaned? What provisionshave been made to make cleaning easy ?


15/104

AN ICE CREAM LABORATORY GUIDEEXERCISE I REPORT


16/104

AN ICE CREAM LABORATORY GUIDE

STANDARDIZATIONOne of the main requirements for a successful icecream business is uniformity of quality. In order to

obtain this, it is necessary to have cream each timecontaining the same percentage of fat. As it is im-possible to always get cream of a uniform fat content,the cream must be standardized. That is, the percent-age of fat must be either increased or decreased to thedesired amount. It is the usual practice to have richercream than is to be used and reduce it by the additionof less rich cream, whole milk, or skim milk. If thecream was lower in percentage of fat than was desired,it could be standardized only by the addition of richercream.

Prof. R. A. Pearson has devised a very simplemethod, known as the rectangular method of standard-ization. This method is as follows : draw a rectangleand place in the center the percentage of fat desired.At the left hand corners place the percentages of fatin the materials to be mixed. It is customary to placethe larger figure at the top, thus:

16 parts of]25% cream]

5 parts ofmilk

= 21 parts"of 20%cream

Then subtract diagonally, placing the remaindersat the right hand corners, as shown above. These


17/104

AN ICE CREAM LABORATORY GUIDE Qshow the proportions by weight in which the materialsmust be mixed to give the desired percentage of fat.A problem may serve to illustrate the method.How many pounds each of 30% cream and 4%milk are necessary to make 260 lbs. of 20% cream?

This shows 16 lbs. 30% cream and 10 lbs. 4% milkmake 26 lbs. of 20% cream, but 260 lbs. is required.This is best solved by simple proportion:

10 lbs. milk : 26 lbs. 20% cream : : x lbs. milk : 260lbs. 20% cream.

Solving X = 100 lbs. 4% milk required and 260 lbs. 100 lbs. milk = 160 lbs. 30% cream required whichmay also be determined by proportion.To be sure no mistakes are made in figuring, it is

best to prove all standardizations. The proof issimple. 260 lbs. 20% cream contains 52 lbs. fat (required).160 lbs. 30% " " 48 lbs. "100 lbs. 4% milk " 4 lbs. "

Making a total of 52 lbs. fat, the amountrequired.

In the above problem a definite amount of the mix-ture was required. There is another class of standard-ization problems in which the amount of one of the


18/104

lO AN ICE CREAM LABORATORY GUIDEmaterials is given, to find the quantity of the other re-quired to standardize it:How much 4% milk must be mixed with 420 lbs. of40% cream to make a mixture testing 25% fat?

This shows that 15 lbs. of 4% milk will standardize21 lbs. of 40% cream to a cream tasting 25% fat. Butthere are 420 lbs. of 40% cream to standardize. Bysimple proportion,

15 lbs. 4% milk : 21 lbs. 40% cream :: x lbs. 4%milk : 420 lbs. 40% cream.

Solving X r= 300 lbs. 4% milk420 lbs. cream + 300 lbs. milk = 720 lbs. 25%

cream.Proof

720 lbs. of 25% cream contains 180 lbs. fat.300 lbs. of 4% milk " 12 lbs. "420 lbs. of 40% cream '' 168 lbs. "

Making a total of 180 lbs. fat.


19/104


20/104

12 AN ICE CREAM LABORATORY GUIDE

EXERCISE NUMBER IISTANDARDIZATION

Cream and milk to standardize will be furnished.Test both by the Babcock method and report the

result to the instructor, who will assign a definite per-centage of fat for the standardized mixture.

After standardizing, test a sample of the standard-ized mixture by the Babcock method to test the ac-curacy of your work.Report all calculations and results on opposite page.


21/104

AN ICE CREAM LABORATORY GUIDE 1EXERCISE II REPORT


22/104


EXERCISE NUMBER IIITESTING ICE CREAM FOR FAT

Ice cream cannot be tested for fat, by the Babcocktest, as milk, because the acid chars the sugar, whichinterferes with the reading. Various methods of test-ing ice cream, so as to overcome this disadvantage havebeen devised. A few of the simpler ones follow.

Test a sample of ice cream by each of the followingmethods and report results on the opposite page.Method of Prof. H. E. Ross: Mix equal parts by

weight of melted ice cream and water. Weigh into a9 gram 50% cream bottle 9 grams of the mixture.Add 17.5 cc. of glacial acetic acid. Shake for two tothree minutes. Next add 15 cc. of sulphuric acidsuch as is used for the Babcock test. Shake for oneminute and proceed as in the ordinary Babcock test.Multiply the reading by two.Method of J. P. Dawson: Weigh 18 grams ofmelted ice cream at a temperature of 70 degrees F.

into a 30%, 9 inch cream test bottle. Add 8 cc. ofglacial acetic acid, agitate gently for 2 minutes and add10 cc. of Babcock sulphuric acid. Shake and centri-fuge in the usual manner.Note : There appears to be no reason why one half

the quantities of ice cream and acids may not be usedin a 6 inch 9 gram 50% cream bottle.Method often used by the authors : Weigh 9 grams

of melted ice cream into a 6 inch 50%, 9 gram creambottle and add about 9 cc. of water. Add threequarters of an acid measure of glacial acetic acid andmix thoroughly. Next add two thirds of an acidmeasure of Babcock sulphuric acid. Shake till wellmixed and centrifuge in the usual manner.


23/104

AN ICE CREAM LABORATORY GUIDE 1EXERCISE III REPORT


24/104

It) AN ICE CREAM LABORATORY GUIDE

EXERCISE NUMBER IVEFFECT OF THE SALT AND ICE MIXTUREON TEMPERATURE

Alake a brine one part salt to ten parts of water by-weight. With part of this fill the can of a handfreezer two thirds full just as though it were an icecream mix which you were going to freeze. Recordthe temperature of this brine.

Trial 1. Using a mixture of one pound of salt to10 lbs. of crushed ice, try freezing the brine in thefreezer can. Turn 10 minutes, keeping the freezercan well covered with the ice and salt mixture. Openand record the temperature of the brine in the can.

Trial 2. Empty the freezer can and tub and refillthe can with more of the brine used in Trial 1. Besure to have it the same temperature. Using a salt andice mixture of the same proportions, pack the tub againand in addition add enough cold water so that it startsto run from the overflow hole in the tub. Turn thefreezer 10 minutes, recording the temperature of thebrine flowing from the overflow hole every 2 minutes.Be sure to keep the ice-salt-water mixture in the tubwell mixed by punching with a stick such as a sawed-ofif broom handle. Again record the temperature ofthe brine in the can. Why does it differ from what itwas in Trial 1 ?

Trial 3. Repeat Trial 2, except use a mixture ofsalt and ice one to six instead of one to 10. Recordresults.

Trial 4. Repeat Trial 3 but do not mix the ice, salt.


25/104

AN ICE CREAM LABORATORY GUIDE I7and water in the tub. Explain the difference in theresults obtained in Trials 3 and 4.

Tabulate and report all the data which you haverecorded.

EXERCISE IV REPORT


26/104

l8 AN ICE CREAM LABORATORY GUIDE

CLASSIFICATION OF ICE CREAMIn the absence of the adoption of any uniform

standard classification of ice cream, the followingclassification in use by the authors is given. It issimple, yet comprehensive, and is arranged accordingto fundamental differences in composition. Thisseems to be the most logical basis for classifying icecream and is very satisfactory from a laboratorystandpoint. Exercises and representative formulaswill be given for each of these classes.

I. Plain or uncooked ice cream, often known asPhiladelphia ice cream, is made from cream, sugar,and flavoring, with or without condensed milk or somestabilizer. It may be subdivided as follows

1. PlainFlavors such as Vanilla, Chocolate, Car-amel, Coffee, Mint, etc.

2. FruitFlavored with fresh or canned fruitssuch as Peach, Pineapple, Strawberry, Cherry,etc.

3. NutFlavored with such nuts as Walnut, Al-mond, Filbert, Chestnut, Pistachio, etc.

4. BisqueFlavored with Marshmallows, Maca-roons, Sponge Cake, Nabisco Wafers, Grape-nuts, etc.

II. Cooked ice cream, often known as French orNeapolitan ice cream, is made from cream, sugar,flavoring, and eggs. As custards they sometimes con-tain flour or cornstarch. The following subdivisionsare recognized:

1. Parfaits or FrenchFlavors such as Vanilla,Chocolate, etc., are most common, but variousfruits are sometimes used.


27/104

AN ICE CREAM LABORATORY GUIDE 12. PuddingsThese are highly flavored with va-

rious dried and candied fruits, nuts, and spices.Examples are Nesselrode, Roman, and Eng-lish Plum.

3. CustardsThese contain flour, cornstarch, tapi-oca, or other similar ingredients, and are al-most always flavored with vanilla.

III. Sherbets and Ices are made from water ormilk, sugar, often egg albumen and a stabilizer, andflavored with fruit juices or other natural flavoring.The most prominent classes are the following

1. IcesMade from water, sugar and some naturalflavoring without eggs or a stabilizer. Thismay include granites and frappes. Granitesare frozen with little agitation, while frappesare only semi- frozen to a slushy consistency.

2. Water Sherbetsare made the same as ices withthe addition of egg whites and sometimes astabilizer. If the whole egg is used, they aresometimes called souffles.

3. Punchesare ices or water sherbets flavoredwith liquors or highly flavored with fruitjuices and spices.

4. Milk SherbetsMade from skimmed or wholemilk, sugar, and egg whites, with or withouta stabilizer and flavored with some naturalflavoring.

5. LactoMade from skimmed or whole sour milkinstead of sweet milk but in other respectsthey resemble milk sherbets.IV. Mousse is a rich cream, sweetened and whipped

to a stifif froth, flavored and frozen in moulds or cans.In the laboratories at the New York state argricul-

tural college 20% cream is used in making all plain oruncooked ice creams. Therefore in the following ex-


28/104

20 AN ICE CREAM LABORATORY GUIDEercises and formulas a 20% cream is used as a base inmost cases. This, however, may be reduced to 18%or 16% if it is thought desirable.

It must be remembered that the formulas given arefor laboratory use and are not especially recommendedas ideal formulas for commercial use. Many of themhave given good results in commercial plants but thereare so many variations and combinations possible thatno single formula or group of formulas can be givenas ideal for all commercial plants.

If the use of condensed milk is desired eight poundsof whole condensed milk may be substituted for thesame amount of cream with excellent results in anyof the formulas given for plain ice cream. Most com-mercial plants use condensed milk to give the ice creammore body and better standing quality.


29/104

AN ICE CREAM LABORATORY GUIDE 21

THE USE OF STABILIZERSA stabilizer of some kind is generally admitted tobe necessary in commercial ice cream. The three mostcommonly used are gelatin, ice cream powders andgum tragacanth.

Gelatin may be prepared in any of the three follow-ing ways, using either milk or water for dissolving it.However, if milk is used, one of the first two methodsshould be used, so as to avoid any cooked flavor fromboiled milk.

1. Using one pint to one quart of water or milk toeach two ounces of gelatin, soak the gelatin in the coldliquid for fifteen to thirty minutes. Then heat themixture up to a temperature of 160 degrees to 170 de-grees F. and add to the cream with rapid agitation.

2. The same as number one, except heat the mix-ture only to a temperature of 125 degrees to 130 de-grees F. for a sufficient time to thoroughly dissolve allof the gelatin.

3. Heat the necessary amount of water to boiling,dump the gelatin into it and stir till dissolved. Thenadd to the cream with rapid stirring.

Ice cream powders should be used according to thedirections given with them.Gum tragacanth stock is made in the followingmanner. Place the dry gum in cold water, using oneounce of gum to four pounds of water. Heat slowlyand uniformly over a low flame or better in a doubleboiler to a temperature of about 110 degrees F. Holdat this temperature for several hours or until the drygum has absorbed all the water it will hold. It doesnot go into true solution in water but will absorb about


30/104

22 AN ICE CREAM LABORATORY GUIDEfifty times its own weight of the water. Strainthrough a coarse strainer and cool. It is then readyfor immediate use. Sometimes enough is made at onetime to last for several days, in which case it is bestto add sufficient sugar to keep it from spoiling.


31/104


32/104

24 AN ICE CREAM LABORATORY GUIDEEXERCISE NUMBER V

FREEZING PLAIN ICE CREAMFreeze ice creams after the following formulas,

which may be reduced to suit the capacity of thefreezer used. Eight pounds of whole condensed milkmay be substituted for eight pounds of the cream ifdesired. Fill out the rec^ord blank on opposite page.

No. 1.40 pounds* of 20% cream8 pounds of sugar4 ounces of vanilla extract4 ounces of gelatin if desired (See page 21)

No. 2.40 pounds of 20% cream8 pounds of sugar2 ounces of vanilla extract4 ounces of gelatin if desired (See page 21)lj4 pounds cocoa dissolved in four pounds of

boiling water with one pound of sugar.(Chocolate may be used.)

Cinnamon to taste if desired.No. 3.40 pounds of 20% cream8 pounds of sugar2 ounces of vanilla extract2 pounds of coffee (boil, strain and use enough

to flavor to taste)4 ounces of gelatin if desired (See page 21)

No. 4.40 pounds of 20% cream8 pounds of sugar1 pint of creme de menth syrup4 ounces of gelatin if desired (See page 21)

Color pale green.


33/104

AN ICE CREAM LABORATORY GUIDE 2^EXERCISE V REPORT

Date Receipt NumberCREAM : ICE CREAM :Age Gallons

Acidity Weight per gallonTemperature SWELL:STANDARDIZATION: Gallons Per cent.Per cent fat in cream.Per cent fat in milk FREEZING:Standardize pounds of Freezer usedcream testing per Pounds ice used...cent fat. Pounds salt used.

TIMEOf starting freezerThat mix reaches 30 FRequired to reach 30 F.That freezing is completedTotal time required toGive proportion. freezeX = the pounds .Pounds of cream used TEMPERATUREPounds of milk used Of mix entering freezer

MIX Of brine when mix reachesPounds Gallons 30 FWeight per gallon Of ice cream when removedPer cent fat it shouldtest Of brine at this timeWas gelatin used? By method 1, 2 or 3?In milk or water?Remarks

Comments on ice cream after it is hardened


34/104


EXERCISE NUMBER VIMETHODS OF MEASURING SWELL

Freeze one or more batches of plain ice cream as as-signed and measure the per cent, of swell in each ofthe following ways. Record results on the oppositepage.Receipt:

40 pounds of 20% cream8 pounds of sugar4 ounces of vanilla extract4 ounces of gelatin if desired (See page 21)

1. Measure the gallons of mix used. Thenmeasure in packing cans the gallons of ice cream ob-tained and calculate the per cent, of swell.

2. Weigh one gallon of the mix. Weigh the firstgallon and the last gallon of ice cream removed fromthe freezer and calculate the per cent, of swell in eachcase.

3. Take two samples, perferably from differentpacking cans of ice cream from the same freezer, anddetermine the per cent, of swell by the method givenin Bulletin 241 of the Wisconsin Station as fohows:Take a 50 cc. sample of ice cream with the samplerfurnished you and transfer to a 300 cc. beaker, usingexactly 200 cc. of hot water to melt it. Then transferall of this to a 250 cc. Florence flask and add 1 or 2 cc.of ether (measured) to reduce the foam. Next addenough water measured from a burette to fill the flaskto the mark. The ether and water required representthe swell. Calculate the per cent, in each case.Which method do you consider the most accurate for

commercial use and why? For experimental use andwhy? Give special advantages of each test.


35/104

AN ICE CREAM LABORATORY GUIDEEXERCISE VI REPORT

27

Date Receipt Number.,CREAMAge

AcidityTemperature

ICE CREAMGallonsWeight per gallon.

STANDARDIZATIONPer cent fat in creamPer cent fat in milkStandardize pounds ofcream testing per

cent fat.

SWELL:Gallons Per cent.

FREEZING:Freezer usedPounds ice used...Pounds salt used.

TIA/[EOf starting freezerThat mix reaches 30 FRequired to reach 30 F.

Give proportion.X r= the poundsPounds of cream used.Pounds of milk used

That freezing is completedTotal time required to

freezeTEMPERATUREOf mix entering freezer

MIXPounds GallonsWeight per gallonPer cent fat it shouldtest

Of brine when mix reaches30 FOf ice cream when removedOf brine at this time.Was gelatin used? By method 1, 2 or 3?.In milk or water?Remarks

Comments on ice cream after it is hardened:


36/104


HARDENING ICE CREAMIce cream may be of the highest quality when re-

moved from the freezer and yet be ruined before itbecomes hard enough to ship unless the hardening isproperly accomplished. The two principal methods inuse are the salt and ice method and the artificiallycooled dry hardening room where the cans of ice creamare simply set in a very cold room and hardened by stillor circulating cold air. The temperature of such aroom should be maintained at near zero F. Witheither method the hardening process should not requiremore than twelve hours. The packing cans shouldalways be cold before they are filled with ice cream, soas to prevent melting in the bottom.

Directions for hardening in salt and ice. Eitherordinary packing tubs or a large box may be used forthis purpose. If tubs are used, simply pack well withsalt and ice mixed in the proportion of one to eight.It is necessary to repack these tubs two or three timesa day in order to keep the ice cream hard. Whenseveral cans of ice cream are to be hardened at a timea better method, more economical in labor and material,is to pack the empty cans up to the covers in a largebox, using salt and ice, one to eight. The soft icecream is poured into these partly packed cans and whenfull they are completely covered with the ice and saltmixture. With such a box it is not necessary to re-pack oftener than twice a day.


37/104


38/104


EXERCISE NUMBER VIIFREEZING FRUIT ICE CREAMHARDEN-ING IN SALT AND ICE

Freeze fruit ice creams after the following formula,using such of the flavors as are assigned. Fill outrecord blank on opposite page.Receipt:40 pounds of 20% cream

8 pounds of sugar4 ounces of gelatin in 4 pounds water3 quarts pulped fruit

Color, if desired.Flavors: Pineapple, raspberry, peach, cherry,

strawberry. Either fresh or canned fruit may be used.If a perpendicular freezer is used, the fruit should

not be added until the ice cream begins to thicken,which will prevent the fruit settling to the bottom ofthe freezer.Harden this ice cream in a salt and ice mixture.


39/104

AN ICE CREAM LABORATORY GUIDEEXERCISE VII REPORT

31

Date Receipt Number.CREAMAge

AcidityTemperature



cent fat.



TIMEOf starting freezerThat mix reaches 30 FRequired to reach 30 F.

Give proportion.X = the poundsPounds of cream used.Pounds of milk used



MIXPounds GallonsWeight per gallonPer cent fat it should

test

Of brine when mix reaches30 FOf ice cream when removedOf brine at this time-

Was gelatin used? By method 1, 2 or 3?.In milk or water?Remarks



40/104


EXERCISE NUMBER VIIINUT ICE CREAM

Freeze nut ice creams as assigned, using the formulagiven below. Fill out the record blank on oppositepage.

Flavors: Walnut, fxlbert, almond and pistachio.It is better if all of these, except the walnuts, areblanched before using by scalding with boiling water

and removing the skins.Prepare the nuts by running them through a meat

chopper and add to the ice cream after it freezesenough to begin to thicken.Receipt:40 pounds of 20% cream8 pounds of sugar2 ounces of vanilla extract4 ounces of gelatin in 4 pounds water3 pounds of nut meats

If pistachio nuts are used, color the ice cream a palegreen.


41/104

AN ICE CREAM LABORATORY GUIDE 33EXERCISE VIII REPORT

Date Receipt Number.

CREAMAge :.AcidityTemperatureICE CREAMGallonsWeight per gallon.


cent fat.





That freezing is completedTotal time required tofreeze

TEMPERATUREOf mix entering freezerMIXPounds GallonsWeight per gallonPer cent fat it should

test

Of brine when mix reaches30 FOf ice cream when removedOf brine at this time.


Comments on ice cream after It is hardened:


42/104


EXERCISE NUMBER IXBISQUE ICE CREAM

Freeze bisque ice cream after the base formula givenbelow, using such of the following flavors as are as-signed. Fill out the record blank on opposite page.

Flavors: Macaroons, sponge cake, grapenuts, andNabisco wafers.Receipt:40 pounds of 20% cream8 pounds of sugar3 ounces of vanilla extract4 ounces of gelatin in 4 pounds water5 pounds pulverized bread product.Any bread product used should be dried sufficiently

so that it may be easily crushed into fine crumbs. Ifperpendicular freezer is used, do not add the crumbsuntil the ice cream freezes enough to begin to thicken.


43/104

AN ICE CREAM LABORATORY GUIDE 35EXERCISE IX REPORT


AcidityTemi5erature


STANDARDIZATIONPer cent fat in creamPer cent fat in milkStandardize pounds ofcream testing. percent fat.


FREEZING:Freezer usedPounds ice used-Pounds salt used.







Was gelatin used? By method 1, 2 or 3?.In milk or water? _Remarks

Comments on ice cream after it is hardened:


44/104


45/104


46/104

38 AN ICE CREAM LABORATORY GUIDEwithdraw the center mold and fill with the straw-berry or chocolate ice cream. Again pack in saltand ice to harden.

Fill a few fancy individual molds and pack inthe salt and ice mixture till hard.Each student should make a 3 layer tri-colored brick.

First prepare the molds, attach your name and pack insalt and ice to become thoroughly cold. As the vanillaice cream is drawn from the freezer fill each mold onethird full and pack in the salt and ice mixture, so thatit will be hardened by the time the strawberry ice creamis ready to be drawn off. Then fill another one thirdwith the strawberry. Finish filling with the chocolate,being sure to have the brick so full of soft cream thatno brine can enter under the lid. Care should be takeneach time to have the bricks set level in the salt and ice.


47/104

AN ICE CREAM LABORATORY GUIDE 39EXERCISE X REPORT

Date Receipt NumberCREAM: ICECREAM:Age GallonsAcidity Weight per gallon.Temperature SWELL:STANDARDIZATION: Gallons Per cent.Per cent fat in cream ___Per cent fat in milk FREEZINGStandardize pounds of Freezer used

cream testing per Pounds ice used...cent fat. Pounds salt used.TIMEOf starting freezerThat mix reaches 30 FRequired to reach 30 F.That freezing is completed

^. . Total time required toUive proportion. freezeX = the poundsPounds of cream used TEMPERATUREPounds of milk used Of mix entering freezer^^ , ^ Of brine when mix reachesPounds Gallons 30 FWeight per gallon Of ice cream when'removedPer cent fat it shouldtest Of brine at this timeWas gelatin used? By method 1, 2 or 3?.In milk or water?Remarks



48/104


49/104

AN ICE CREAM LABORATORY GUIDE 4I

EXERCISE NUMBER XICUSTARD ICE CREAMFreeze custard ice creams after the following re-

ceipts as assigned and fill out report blank on oppositepage. Quantities given are for hand freezers.Receipts:

No. 1.6 quarts of milk3 pounds of sugar

24 eggs12 tablespoonfuls of cornstarch6 tablespoonfuls of vanilla or to taste.

Put the milk over the fire in a farina or double waterboiler. Moisten the cornstarch with a little cold milkso that it can be added to milk without lumping.When the milk is hot, add the cornstarch and stir untilit begins to thicken. Beat the eggs and sugar togetheruntil light and then add them to the hot milk. Cooka few minutes, take from fire, flavor and cool andfreeze same as ice cream.Other flavors as coffee or chocolate may be made by

substituting these flavors for the vanilla.No. 2.

5 quarts milk1 quart 30% cream8 eggs2}4 pounds sugar %6 tablespoonfuls flourI3/2 ounces of vanilla or to taste

Follow directions given for No. 1.


50/104

42 AN ICE CREAM LABORATORY GUIDENo. 3.2 quarts 30% cream4 quarts of milk3 pounds of sugar1^ quarts Minute Tapioca

yolks of 4 eggs1 teaspoonful salt4 teaspoonfuls lemon extract2 teaspoonfuls rose extract

Cook the tapioca in two quarts of milk for 10minutes, then add the rest of the milk, the sugar andsalt. Cook ten minutes longer. Remove from fire andadd the egg yolks well beaten. Then add the extract,cool, and freeze. When nearly done, add the creampreviously beaten to stiff froth and finish freezing.


51/104

AN ICE CREAM LABORATORY GUIDEEXERCISE XI REPORT

43

Date Receipt Number....CREAMAgeAcidityTemperature


STANDARDIZATIONPer cent fat in creamPer cent fat in milk.Standardize pounds ofcream testing percent fat.












52/104


53/104


EXERCISE NUMBER XIIPARFAIT OR FRENCH ICE CREAM

Freeze the following receipts as assigned and fill outreport blank on opposite page.Receipts:

No. 1.40 pounds of 20% cream10 pounds of sugar4 ounces of vanilla extract8 dozen eggs well beaten

Beat the egg yolks till smooth, add the sugar, andbeat again till it is dissolved. Beat the whites to a stifYfroth and stir into the yolks and sugar. Mix all withthe cream and cook in a double boiler to a temperatureof 180 degrees F. for 15 minutes. Cool to 40 degreesF., add vanilla and freeze.

No. 2.40 pounds of 28% cream10 pounds of sugar4 ounces of vanilla extract8 dozen eggs well beaten2 quarts crushed strawberries

Beat whole eggs together, add to the mix and freeze,or the whites may be beaten separately if desired andadded after the mix is partly frozen.

No. 3.40 pounds of 25% cream12 pounds of sugar4 ounces of vanilla extract4 pounds chopped walnut meats

yolks of 8 dozen eggs


54/104

46 AN ICE CREAM LABORATORY GUIDEBeat the egg yolks till smooth, add the sugar and

beat again. Then add to the cream and cook in doubleboiler to 180 degrees F. for 15 minutes. Cool, add thebalance of the mix and freeze.


55/104

AN ICE CREAM LABORATORY GUIDEEXERCISE XII REPORT

47


AcidityTemperature

ICE CREAMGallonsWeight per gallon.STANDARDIZATIONPer cent fat in creamPer cent fat in milk

Standardize pounds ofcream testing percent fat.










Comments on ice cream after It is hardened:


56/104


57/104


EXERCISE NUMBER XIIIPUDDINGS

Freeze the following puddings as assigned and fillout report blank on opposite page.Receipts:

No. 1.Nesselrode.32 pounds 28% cream10 dozen eggs10 pounds of sugar6 ounces vanilla4 pounds chopped walnut meats3 pounds chopped candied cherries3 pounds chopped candied fruits4 pounds chopped raisins

Cook the ^gg yolks with the cream. Beat the whitesand add when partly frozen.No. 2English Plum.

32 pounds 25% cream8 dozen eggs12 pounds sugar3 pounds cocoa or chocolate5 pounds assorted fruits that do not pulp2 pounds seeded raisins3 pounds dates4 pounds walnut meats4 tablespoonfuls ground cinnamon1 tablespoonful ginger1 tablespoonful ground cloves

Use the eggs as directed under receipt number one.Chop the fruits and nuts fine.


58/104

50 AN ICE CREAM LABORATORY GUIDENo. 3.Fruit Pudding

32 pounds 10% cream8 pounds whole condensed milk8 pounds of sugar5 ounces of gelatin dissolved in part of cream2 pounds chopped cherries2 pounds chopped raisins2 pounds chopped nuts1^ quarts sherry wineSoak the fruit over night in the sherry wine.


59/104

AN ICE CREAM LABORATORY GUIDE 5EXERCISE XIII REPORT


AcidityTemperature

ICE CREAMGallonsWeight per gallon.STANDARDIZATIONPer cent fat in creamPer cent fat in milkStandardize pounds ofcream testing percent fat.










Comments on ice cream after It is hardened


60/104


EXERCISE NUMBER XIVICES

Freeze the following water ices as assigned and fillout record blank on opposite page.Receipts:

No. 1.48 pounds of water20 pounds of sugar6 pounds of lemon juice

No. 2.48 pounds of water20 pounds of sugar2 pounds of lemon juice4 quarts pineapple juice

No. 3.48 pounds of water20 pounds of sugar2 pounds of lemon juice4 quarts finely pulped strawberries

No. 4. Same as number two, except freeze veryrapidly with little agitation. This is oftencalled a granite.


61/104

AN ICE CREAM LABORATORY GUIDE 53EXERCISE XIV REPORT


AcidityTemperatureICE CREAMGallonsWeight per gallon.

STANDARDIZATIONPer cent fat in creamPer cent fat in milkStandardize pounds ofcream testing percent fat.

SWELLGallons Per cent.

FREEZINGFreezer usedPounds ice used-Pounds salt used.










62/104


EXERCISE NUMBER XVWATER SHERBETS

Freeze the following sherbets as assigned and fill outrecord blank on opposite page.Receipts:

No. 1.48 pounds water16 pounds sugar

1 pound lemon juice4 quarts grated pineapple (or pineapple juice)6 ounces of gelatin in 4 pounds of water, if de-

sired24 Qgg whites beaten stiff and added when mix-

ture is partly frozenNo. 2. Same as number one except replace the pine-

apple with grape juice.No. 3. Use same mix as number one except re-

place the pineapple with orange juice.Boil the water and sugar to a clear syrup,then strain and cool before freezing.


63/104

AN ICE CREAM LABORATORY GUIDE 55EXERCISE XV REPORT


AcidityTemperature

ICE CREAMGallonsWeight per gallon.STANDARDIZATIONPer cent fat in creamPer cent fat in milkStandardize pounds ofcream testing percent fat.



TIMEOf starting freezerThat mix reaches 30 F.Required to reach 30 F.



freezeTEMPERATURE ~Of mix entering freezer


test





64/104


EXERCISE NUMBER XVIMILK SHERBETS

Freeze milk sherbets after the following base for-mula, using such of the flavorings as are assigne !.Fill out the record blank on the opposite page.

Flavors : Orange, grape, cherry, pineapple, andstrawberry. If lemon is desired, use only two quartsof lemon juice with a quart of orange juice.Receipt:

48 pounds of milk16 pounds of sugar5 ounces of gelatin in 2 quarts water1 pound lemon juice4 quarts fruit flavoring12 Qgg whites beaten stiff and added after mix-

ture is partly frozen.


65/104

AN ICE CREAM LABORATORY GUIDE CyEXERCISE XVI REPORT

P^^^ Receipt NumberCREAM: ICECREAM:Age Gallons^^ature-z:::::::::; ^^'^'^^ p- ^'^-SWELLSTANDARDIZATION: Gallons PercentPer cent fat in cream Per cent fat in milk FREEZING-Standardize pounds of Freezer usedcream testing per Pounds ice usedc^"t fat. Pounds salt used

TIMEOf starting freezerThat mix reaches 30 F..""Required to reach 30 RThat freezing is completed

Give proportion. "^"freeze'" "^^'^ "^X =3 the pounds -^Pounds of cream used TEMPERATUREPounds of milk used Of mix entering freezer^Pounds Gallons ^\^o%' ^^^" "^^" ^^^^^^^'^s'^'Lir g^^^^-shouid ^^.^-:::^^^^^- Of brine at this timeWas gelatin used? By method 1, 2 or 3?In milk or water?Remarks



66/104


EXERCISE NUMBER XVIIPUNCHES AND LACTO

Freeze the following formulas as assigned and fillout the record blank on opposite page:Punches:

No. 1.48 pounds water20 pounds sugar1 pound lemon juice1 quart brandy and rum mixed

No. 2.48 pounds water20 pounds sugar

1 pound lemon juice1 quart orange juice2 quarts wine4 ounces gelatin in part of the water

No. 3.48 pounds water20 pounds sugar1 quart lemon juice1 quart raspberry juice1 quart grape juice

cloves, cinnamon, allspice and nutmeg to taste.Lacto (From Iowa Station Bulletin 140)

48 pounds good starter just nicely coagulated18 pounds sugar24 eggs, whites and yolks beaten separately2 quarts of grape juice1^ quarts lemon juiceMix in the order given in the formula. Other

flavors may be substituted for the grape juice.


67/104

AN ICE CREAM LABORATORY GUIDE $9EXERCISE XVII REPORT


AcidityTemperature

ICE CREAAi:GallonsWeight per gallon.

STANDARDIZATIONPer cent fat in cieamPer cent fat in milkStandardize pounds ofcream testing percent fat.

-


68/104

6o AN ICE CREAM LABORATORY GUIDE

EXERCISE NUMBER XVIIIMOUSSE

Prepare and freeze mousse after the followingformulas as assigned.

No. 1.For five gallons20 pounds aged sweet cream, at least 40% fat5 pounds sugar6 ounces of gelatin

juice of three lemons3 quarts strained strawberry juice

Dissolve the sugar in the fruit juice, then stir in thegelatin dissolved in a very little water. Chill thismixture but not enough to form a jelly. Whip the coldcream till stiff and then fold in the gelatin-sugar-fruitmixture.

Pack into molds or cans and harden in a salt and icemixture one to two. Other flavors may be substituted.

No. 2.For five gallons20 pounds of aged sweet cream, 35% fat4 pounds of sugar5 ounces of gelatin2^ ounces of vanilla

Dissolve the gelatin and stir into the cream. Whiptill stiff, then fold in the sugar and vanilla and pack incans, hardening in salt and ice mixed one to two.

Report results on opposite page.


69/104

AN ICE CREAM LABORATORY GUIDE ' 6lEXERCISE XVIII REPORT


70/104

(i2 AN ICE CREAM LABORATORY GUIDE

EXERCISE NUMBER XIXSTANDARDIZE MIX TO A GIVEN PERCENT-AGE OF FATThe following materials will be furnished : cream,

milk, sugar, chocolate, fruit, vanilla and gelatin. Fromthem make up a receipt and freeze a batch of ice creamto contain a given per cent, of fat as assigned.

Test the frozen ice cream for fat and report the re-sult to the instructor at time of testing.

Include your receipt and all calculations and testson opposite page.Mark plainly each can of ice cream with the receiptnumber, your name, and the date.

No. 1. Vanilla ice cream to test 14% fat.No. 2. Vanilla ice cream to test 12% fat.No. 3. Vanilla ice cream to test 9^% fat.No. 4. Fruit ice cream to test 11% fat.No. 5, Chocolate ice cream to test 12% fat.


71/104

AN ICE CREAM LABORATORY GUIDEEXERCISE XIX REPORT

63


AcidityTemperature

ICE CREAM:GallonsWeight per gallon.STANDARDIZATIONPer cent fat in creamPer cent fat in milkStandardize pounds ofcream testing percent fat.




Give proportion.21 = the poundsPounds of cream used.Pounds of milk used




Of brine when mix reaches30 FOf ice cream when removedtest. Of brine at this time.




72/104


SCORE CARD FOR ICE CREAMThe comparison of ice creams is accomplished best

by reducing their quahty to a numerical basis. Thisis done by use of a score card. Two score cards aresuggested as follows

Modification of theCornell Score Card Wisconsin Score Card

Flavor 45 Flavor 40Body and texture 35 Body and texture 25Richness 10 Bacterial count 15Appearance 5 Richness 10Package 5 Appearance 5Package 5

100 100It may be more advantageous to use the Cornell score

card in the Laboratory because immediate results canbe obtained, while with the modified Wisconsin scorecard bacterial counts must be made of the ice cream, sothat it would be two to three days before the final scoreof the ice cream could be obtained.

Discussion of Qualities of Ice CreamFlavor. The ice cream should have a pronounced

flavor which will blend with the flavor of the cream togive a clean, desirable typical flavor.Body and Texture. The body should be firm and

mellow. It should not be tough or rubbery neithersoft or mushy. The texture should be smooth andvelvety and entirely free from graininess and lump-iness.

Richness. If the ice cream meets the legal require-ments, it should be given a perfect score. If it fallsbelow the legal requirement, it should be scored zero.


73/104

AN ICE CREAM LABORATORY GUIDE 65Appearance. The ice cream should have an at-

tractive appearance and be of the characteristic uniformcolor.

Package. The package should be neat and cleanand, if for long shipment, some provision should bemade to protect the ice on top of the packing tub.Bacterial count. An ice cream which has a count of

20,000 should be considered perfect. For each in-crease of 20,000 above this one point should be de-ducted from the score.

Application of score card. When judging samplesof ice cream, it is best to try some of them to obtainsome idea of the qualities of the samples to be scored.This is necessary so that the score will not run above100 and to set a standard. Then with a definite stand-ard in mind, the samples may be carefully scored. Thecuts in score should be made in proportion to thequality of the ice cream and the definite standard inmind.


74/104


EXERCISE NUMBER XXJUDGING PLAIN ICE CREAM

Score and criticize the samples of plain ice creamrecording the scores on the opposite page. (For scorecard see page 64.)One sample will first be scored by the instructor asan example and guide to the severeness of the cut fordifferent defects. After the students have finished, hewill score the remaining samples with them.

Three of the samples are ice cream made in thecollege laboratory. The others are purchased andrepresent well known commercial ice creams.

After scoring on all other points make a fat test ofeach sample. (See page 14.)


75/104



76/104


EXERCISE NUMBER XXITHE EFFECT OF FAT CONTENT ON ICECREAMPart I. Freeze ice creams after the following for-

mulas as assigned.. Each has a different percentage offat. Fill out the record blank on opposite page andmark plainly each can of ice cream with the receiptnumber, your name and the date.Receipts:

No. 1.40 pounds of 10% cream8 pounds of sugar4 ounces of vanilla extract4 ounces gelatin in 4 pounds water.

No. 2. Same as No. 1 except use 15% cream.No. 3. Same as No. 1 except use 20% cream.No. 4. Same as No. 1 except use 30% cream.No. 5. Same as No. 1 except use 40% cream.Part II. After hardening or next laboratory period

score and criticize the ice cream made in Part I. Fillin the score blank on page 90.


77/104

AN ICE CREAM LABORATORY GUIDE 69EXERCISE XXI REPORT

PARTIDate Receipt Number.

CREAMAgeAcidityTemperature

ICE CREAA!GallonsWeight per gallon.

STANDARDIZATIONPer cent fat in creamPer cent fat in milkStandardize pounds ofcream testing percent fat.

-

an ice cream factory (1917)

Documents