3. Repeat 32,1, but increase the gelatin to 5.8 grams and reduce the cold water to 172 cc. What is the percentage of gelatin used? Its measure?

4. Repeat 32,1, but increase the gelatin to 7.2 grams and decrease the cold water to 171 cc.

5. Repeat 32,1, but decrease the gelatin to 2.4 grams and increase the cold water to 192.5 cc.

Gelatin, grams

Gelatin, measure

Gelatin, per cent

Time to set

Temperature when set

Texture

Results and conclusions.

Experiment 33

To determine the effect of high temperatures upon the stiffening power of gelatin.

A. Plain gelatin.

1. Hydrate 3.5 grams of gelatin with 30 cc. of cold water. Cover the bowl to prevent the steam from condensing in the bowl and increasing the quantity of liquid in the gelatin. If the quantity of liquid is increased, measure it and decrease the cold water added accordingly. Place the covered bowl in a pressure cooker and heat for 15 minutes at 15 pounds pressure. Take from the cooker and add 176.5 cc. of cold water, 30 cc. of lemon juice, and 50 grams of sugar.

2. Repeat A1, but after hydrating add the lemon juice to the gelatin before heating in the pressure cooker.

3. Hydrate 3.5 grams of gelatin in 30 cc. of cold water. Melt over hot water, then add 176.5 cc. of cold water, 30 cc. of lemon juice, and 50 grams of sugar.

Does hydrolysis occur more rapidly when the gelatin contains an acid or when plain? Does the one with the acid ever become stiff enough to serve?

B. Acidulated gelatin.

Repeat the directions under 33A, but use acidulated gelatin. Notice the proportions given on the package for a cup of liquid and use the part of a package needed for a cup of the gelatin solution. What is its weight and measure? Make up 1 cup without heating in the cooker for a control. Compare with A for time required to set and the texture of the gelatin.

Experiment 34

To determine the effect of sugar upon the texture of a gelatin jelly.

1. Hydrate 3.5 grams of gelatin with 30 cc. of cold water. Dissolve by warming over hot water, then add 176.5 cc. of cold water, and 30 cc. of lemon juice.

2. Hydrate 3.5 grams of gelatin with 30 cc. of cold water. Dissolve by warming over hot water, then add 176.5 cc. of cold water, 30 cc. of lemon juice, and 50 grams of sugar.

3. Hydrate 3.5 grams of gelatin with 30 cc. of cold water. Dissolve by warming over hot water, then add 176.5 cc. of cold water, 30 cc. of lemon juice, and 100 grams of sugar. Compare the stiffness of the gelatins and the time required to set. If desired the lemon juice may be omitted in Experiment 34 and the cold water increased to 206.5 cc. This will show the effect of the sugar upon gelation and the stiffness of the jelly without the added lemon juice.

Sugar, grams

Time to set

Temperature when set

Texture

Effect of sugar on texture

Results and conclusions.

Experiment 35

To determine the effect of fresh pineapple on the gelation property of gelatin.

Hydrate 7 grams of gelatin with 60 cc. of cold water. Dissolve by warming over hot water, then add 330 cc. of cold water, 60 cc. of lemon juice, and 100 grams of sugar. Divide into two equal portions.

1. To part one add 2 tablespoons of grated raw pineapple. Cool.

2. To part two add 2 tablespoons of cooked grated pineapple. Cool. Does the gelatin containing the uncooked pineapple gel? Why? What is the effect of cooking upon the pineapple? Results.

Experiment 36

To determine the effect on the texture of gelatin of beating and the addition of whipped cream and beaten egg white.

Make up 4 cups of lemon jelly by hydrating 14 grams of gelatin with 120 cc. of cold water. Dissolve by warming over hot water, then add 720 cc. of cold water, 120 cc. of lemon juice, and 200 grams of sugar. Divide into 4 equal parts. Metal quart cups are good to use for gelatins that are to be beaten as the volume may be measured without removing from the container.

1. Cool.

2. Cool until it becomes thick enough to beat. Beat with an egg beater until the volume increases. Cool until firm. Obtain volume.

3. Repeat 36,2, but after beating fold in a stiffly beaten egg white. Cool until firm. Obtain volume.

4. Repeat 36,2, but after beating fold in 1/2 cup of whipped cream. Cool until firm. Obtain volume.

Compare for volume, flavor, texture, and number of servings obtained. Does the volume increase or decrease when the whipped cream is folded into the gelatin? Is the above proportion of lemon juice best for both a plain jelly and a beaten jelly? What proportion of lemon juice and sugar would you suggest for a plain jelly? For a beaten jelly?

Volume

Number of servings

Texture

Flavor

Results and conclusions.