A text-book of cooking

the cellular framework separates the starch grains so that they are uniformly cooked. Since there is nothing to separate the grains in a powdered starchy substance, it becomes necessary to mix it with certain materials so that the heat and moisture can penetrate every grain at the same time. Experiment 20 : Separation of Starch Grains with Cold Water. — Mix 1 teaspoonful of flour with 1 teaspoonful of water. Add 2 tablespoonfuls of boiling water, stir, and heat. Is the mixture smooth ? Explain clearly the use of cold water in this mixture. Experiment 21: Separation of Starch Grains with Sugar. — Mix 1 teaspoonful of flour with 1 teaspoonful of sugar. Add 2 tablespoonfuls of boiling water, stir, and heat. Is the mixture smooth ? Carefully explain the use of sugar in the mixture. Experiment 22 : Separation of Starch Grains with Fat. — Mix 1 teaspoonful of flour with 1 teaspoonful of fat. Add 2 tablespoonfuls of boiling water, stir, and heat. Is the mixture smooth ? Explain the use of fat in this mixture. BLANC MANGE 2 cupfuls milk 2 teaspoonfuls vanilla J cupful cornstarch Nutmeg J cupful sugar Salt Scald the milk in a double boiler. Mix the sugar and cornstarch. Add the hot milk slowly to the sugar and cornstarch mixture, stirring rapidly. Return to the double boiler and cook 30 minutes, stir rapidly until the mixture thickens. Add the salt and flavoring and pour into a mold which has been moistened with cold water. Cool, turn from the mold, and serve with sugar and cream. CHOCOLATE CORNSTARCH PUDDING Proceed as for Blanc Mange, using f cupful of sugar instead of J cupful. Cut into pieces 1 square of Baker's chocolate. Add to it \ cupful of boiling water. Stir and TOAST : DIGESTION OF STARCH 55 heat until smooth and thoroughly blended. Add this to the cornstarch mixture just before taking from the fire. Add £ teaspoonful of vanilla. Mold and serve as Blanc Mange. Name three substances that can be used to prevent the lumping of powdered cereals used for thickening. Give the .reason for mixing the sugar, cornstarch, and hot milk of Blanc Mange as directed. For how long a time after placing in the double boiler is it necessary to stir the cornstarch, sugar, and hot milk mixture ? Note the number of minutes that is required to thicken the mixture and the length of time of cooking given in the recipe. Why is it necessary to cook the mixture for so long a time after it thickens ? (See Cereals, p. 39.) Why is Blanc Mange cooked entirely over boiling water, and not over the flame and then in a double boiler, as cereals ? Why is the flavoring not added while the mixture is cooking ? What is the price per package of cornstarch ? How much does a package of cornstarch weigh and measure ? Which material — flour or cornstarch — is the cheaper to use for thickening ? How many persons does the above quantity of Blanc Mange serve ? LESSON XIII Toast : Digestion of Starch Experiment 23 : Change of Starch into Dextrin. — Place a teaspoonful of flour in a frying pan and heat slowly until it becomes very dark brown and uniform in color. Put a little of the browned flour into a test tube, add water, then shake. Add a few drops of iodine. What indicates the presence of starch ? Is starch present ? The starch has been changed to dextrin. Dextrin gives a purple (port-wine) color when treated with iodine. Experiment 24 : The Solubility of Dextrin. Pour the remainder of the browned flour from Experiment 23 into a test tube. Add water A and shake. Four through filter paper 1 into another test tube. (See Fig. 22. ) Notice the color of the liquid that has been filtered. Add a few drops of iodine to the filtered liquid. Is dextrin present? Is dextrin soluble in water ? d Fig. 22. — Method of folding filter paper.