EXERCISE NUMBER VI

METHODS OF MEASURING SWELL

Freeze one or more batches of plain ice cream as assigned and measure the per cent. of swell in each of the following ways. Record results on the opposite page.

Receipt:

40 pounds of 20% cream

8 pounds of sugar

4 ounces of vanilla extract

4 ounces of gelatin if desired (See page 21)

1. Measure the gallons of mix used. Then measure in packing cans the gallons of ice cream obtained and calculate the per cent. of swell.

2. Weigh one gallon of the mix. Weigh the first gallon and the last gallon of ice cream removed from the freezer and calculate the per cent. of swell in each case.

3. Take two samples, preferably from different packing cans of ice cream from the same freezer, and determine the per cent. of swell by the method given in Bulletin 241 of the Wisconsin Station as follows: Take a 50 cc. sample of ice cream with the sampler furnished you and transfer to a 300 cc. beaker, using exactly 200 cc. of hot water to melt it. Then transfer all of this to a 250 cc. Florence flask and add 1 or 2 cc. of ether (measured) to reduce the foam. Next add enough water measured from a burette to fill the flask to the mark. The ether and water required represent the swell. Calculate the per cent. in each case.

Which method do you consider the most accurate for commercial use and why? For experimental use and why? Give special advantages of each test.

EXERCISE VI REPORT

Date_________________________ Receipt Number_______________

CREAM: ICE CREAM:

Age _______ Gallons _______

Acidity _______ Weight per gallon _______

Temperature _______

SWELL:

STANDARDIZATION: Gallons________ Per cent. _______

Per cent fat in cream _______

Per cent fat in milk _______ FREEZING:

Standardize_______ pounds Freezer used _______

of cream testing _______ Pounds ice used _______

per cent fat. Pounds salt used _______

TIME:

Of starting freezer _______

That mix reaches 30° F _______

Required to reach 30° F _______

That freezing is completed _______

Total time required to freeze _______

Give proportion.

x = the pounds _______

Pounds of cream used _______ TEMPERATURE:

Pounds of milk used _______ Of mix entering freezer _______

Of brine when mix reaches 30° F _______

MIX: Of ice cream when removed _______

Pounds _______ Of brine at this time _______

Gallons _______

Weight per gallon _______

Per cent fat it should test _______

Was gelatin used? _______ By method 1, 2 or 3? _______

In milk or water? _______

Remarks:

Comments on ice cream after it is hardened:

HARDENING ICE CREAM

Ice cream may be of the highest quality when removed from the freezer and yet be ruined before it becomes hard enough to ship unless the hardening is properly accomplished. The two principal methods in use are the salt and ice method and the artificially cooled dry hardening room where the cans of ice cream are simply set in a very cold room and hardened by still or circulating cold air. The temperature of such a room should be maintained at near zero F. With either method the hardening process should not require more than twelve hours. The packing cans should always be cold before they are filled with ice cream, so as to prevent melting in the bottom.

Directions for hardening in salt and ice. Either ordinary packing tubs or a large box may be used for this purpose. If tubs are used, simply pack well with salt and ice mixed in the proportion of one to eight. It is necessary to repack these tubs two or three times a day in order to keep the ice cream hard. When several cans of ice cream are to be hardened at a time a better method, more economical in labor and material, is to pack the empty cans up to the covers in a large box, using salt and ice, one to eight. The soft ice cream is poured into these partly packed cans and when full they are completely covered with the ice and salt mixture. With such a box it is not necessary to repack oftener than twice a day.