40 pounds of 20% cream 8 pounds of sugar 4 ounces of vanilla extract 4 ounces of gelatin in 4 pounds water Freeze the first batch as a preliminary one. Regulate either the temperature or quantity of brine so that the second batch will freeze in four minutes, the third in fifteen minutes, and the fourth in thirty minutes. Note particularly the effect on the swell and quality. Fill out the record blank on opposite page. EXERCISE XXVII REPORT =========================+=====+=====+=====+===== Batch Number | 1 | 2 | 3 | 4 -------------------------+-----+-----+-----+----- Pounds of Mix | | | | -------------------------+-----+-----+-----+----- Gallons of Mix | | | | -------------------------+-----+-----+-----+----- Temperature of Mix | | | | -------------------------+-----+-----+-----+----- Time of Starting Freezer | | | | -------------------------+-----+-----+-----+----- Time of Stopping Freezer | | | | -------------------------+-----+-----+-----+----- Temperature of Ice Cream | | | | -------------------------+-----+-----+-----+----- Gallons of Ice Cream | | | | -------------------------+-----+-----+-----+----- Gallons of Swell | | | | -------------------------+-----+-----+-----+----- Per Cent of Swell | | | | -------------------------+-----+-----+-----+----- Comments: EXERCISE NUMBER XXVIII BACTERIAL COUNTS OF ICE CREAM This exercise is to be performed once during the course by each student as assigned. Sterile glassware and media will be furnished you. Weigh or measure the samples for dilution as instructed. Take samples as indicated below in sterile bottles and plate on plain lactose agar. Incubate at 37 degrees C., for 48 hours. Sample of cream. Dilutions ¹/₁₀,₀₀₀ and ¹/₁₀₀,₀₀₀. Sample of gelatin. Dilutions ¹/₁₀ and ¹/₁₀₀. Sample of vanilla. Dilutions ¹/₁₀. Sample of sugar. Dilutions ¹/₁₀. Sample of mix. Dilutions ¹/₁₀,₀₀₀ and ¹/₁₀₀,₀₀₀. Sample of ice cream from freezer. Dilutions ¹/₁₀,₀₀₀ and ¹/₁₀₀,₀₀₀. Sample of ice cream after it has remained in the hardening room one week. Make dilutions of ¹/₁₀,₀₀₀ and ¹/₁₀₀,₀₀₀. Report results on the blank page opposite. EXERCISE XXVIII REPORT EXERCISE NUMBER XXIX TESTING SAMPLES OF GELATIN Weigh 5 gram samples of gelatin into 100 cc. of cold water in beakers or jelly glasses. Allow it to soak over night. Then heat slowly, with stirring, to 80 degrees C. Subject to the following tests and make report on opposite blank page. 1. Note the odor. 2. Determine the time required for 50 cc. to run from a pipette. 3. Determine the time required for the sample to gelatinize.