Cooking Eggs in Water

Experiment 63

I. In the shell.

A. To determine the effect of coagulation at different temperatures on the texture of the white and yolk.

1. Cook an egg in water. Do not let the temperature of the water go above 72°C. It is easier to control the temperature, if a large quantity of water is used and the heat is turned low after the desired temperature is reached. Cook from 1 to 1 1/4 hours.

2. Cook an egg in water the temperature of which does not go above 85°C. Cook 30 to 35 minutes.

3. Cook two eggs in boiling water. Cook 12 to 15 minutes.

a. Cool one egg slowly, leaving it in the water in which it was cooked.

b. Cool the other egg rapidly, letting cold water from faucet run over it until cold.

Compare with the eggs from 1 and 2 in texture and firmness of the white and yolk. Which gives a tender and desirable product for eating? For slicing? Do any have a green layer at the junction of the white and yolk?

Texture

Tenderness

Comments

White

Yolk

White

Yolk

Results and conclusions.

B. To determine the effect of cooking for varying lengths of time at a high temperature upon the texture and consistency of egg white and yolk. Cook in boiling water.

1. Cook 2 minutes.

2. Cook 3 minutes.

3. Cook 5 minutes.

4. Cook 7 minutes.

5. Cook 10 minutes.

Compare the consistency of the white and yolk cooked for varying lengths of time. Compare with results obtained in A.

II. Out of the shell.

A. To determine the method of obtaining a desirable poached egg.

Use a pan deep enough so that water will entirely cover the egg. Add a pint of water. Use more water if necessary, but all should use the same quantity. A film of fat rubbed over the bottom of the pan before the water is added seems to help prevent the egg from sticking to the pan. Have the water boiling when the egg is added. Keep the water bubbling very slowly. (For edible purposes it is better to keep the water below the boiling point after the egg is added, but the temperature of the water in different pans may vary widely. Hence, keeping the water boiling very slowly serves for comparative purposes.) Cook 3 minutes. Start with fresh water for each experiment. Break the egg into a sauce dish just before adding to the water. Slide it carefully into the water. Study the structure of one egg after it is broken out of the shell. Note the proportion of thick and thin white, for this will vary with different eggs. If very different in some individual eggs, cook and repeat one part of the experiment, to see if you get the same results the second time. Note the chalazae. Do any spots appear on the yolk?

A. Fresh eggs.

1. Cook in plain water.

2. Add 3/4 teaspoon of salt per pint of water.

3. Add 1 teaspoon of vinegar per pint of water.

4. Decide which of the three experiments above gives the best-appearing product, then repeat it; but swirl the water around the pan, dropping the egg in the center.

B. Eggs deteriorated so that they have a larger proportion of thin white.

1. Repeat A1.

2. Repeat A2.

3. Repeat A3.

4. Repeat A4.

C. Repeat A1, using a ring placed in the bottom of the pan in which the egg is placed. Or use any type of cup made for poaching eggs.

Which coagulates better, the thick or thin portions of the egg white? What is the effect of adding salt? Vinegar? Would the technic in swirling the water make any difference in the result? Why not swirl too hard? If eggs are cooked at a lower temperature, should the time be increased?

Do you wish to try changing the proportion of salt? The time and temperature of cooking?

White

Yolk

Extent of coagulation

Texture

Extent of coagulation

Texture

Comments

Conclusions.

Custards

Experiment 64

To determine the factors that affect the coagulation and curdling of custards. Recipe:

Milk

Egg Sugar

1 cup

2 tablespoons

244 grams 48 grams 25 grams

A. To determine the effect of rate of coagulation upon the texture and consistency of custards.

1. Prepare 2 times the recipe, then divide into equal parts; use part one for Al, and part two for A2. It is better for two or more students to work together for this experiment. Combine all the ingredients and mix thoroughly. Put one part in the upper part of a double boiler. The boiler should be rather deep to have the custard sufficient to cover the thermometer bulb when portions of the custard are removed. A double boiler holding a quart and about 4 inches in depth is satisfactory. Add a pint of cold water to the lower part; then put the upper portion of the double boiler into the lower. Make a record of the temperature of the custard mixture and the time. Put over the fire and heat. The heating may be rapid until the custard mixture reaches a temperature of 70°C. Then the heat should be regulated so that at least 1 to 1 1/2 or more minutes will be required to elevate the temperature 1°C, i.e., about 3 minutes should be required for the temperature of the custard to go from 80° to 82°. One student may hold the thermometer and read the temperatures; a second can record the time and temperature. Record the time every 5° during the first period of heating, i.e., 30°, 35°, etc. But record the time for 1° rise after 78° is reached, i.e., at 78°, 79°, 80°, 81°, etc. A third student may stir the custard and a fourth can remove portions of the custard. It is easier to let the bulb of the thermometer touch the bottom in the center of the double boiler. Use a wooden spoon for stirring. Have dishes ready to put the custard in. Bend the bowl of an old metal spoon until it is at right angles to the handle. Use it for removing portions of the custard, taking out 2 tablespoons at each temperature. Remove portions of the custard at 78°, 80°, 82°, 84°, 86°, 88°, and when curdled.