See Chocolate Corn-starch Pudding. How much cocoa may be used for 1 ounce of chocolate when one is substituted for the other? What is the difference in cost of these quantities of chocolate and cocoa?
LESSON XLVIII
MILK AND CREAM
WHIPPING CREAM.—A popular way of preparing cream for serving is to whip it. This is done most successfully when the cream is cold and kept cold, i.e. surrounded with ice water during the beating process.
To show one of the points involved in chilling materials try the following:
EXPERIMENT 46: COMPARISON OF THE CONDUCTING POWER OF METAL AND EARTHENWARE.—Select a tin and an earthenware utensil of about the same size and shape. Put an equal quantity of water of the same temperature in each utensil. Surround each with ice water and cover. After 5 minutes, take the temperature of the water in the tin and in the earthenware utensil. Which is colder? Through which material,—tin or earthenware,—is heat transmitted more readily? When cream is to be surrounded by ice water for whipping, in which kind of utensil should it be placed? Explain your answer.
Use a Dover egg beater or a cream whip for whipping cream. Since cream "spatters" when being beaten, a cream whip arranged with a cover is very satisfactory. To prevent spattering, the bowl of cream may be covered with paper while the cream is being whipped. Cut a slit in a piece of paper, insert the Dover egg beater in the slit, put the beater in the cream and push the paper down to cover.
Since cream contains considerable fat, under certain conditions, it is possible to mass the fat together, that is, separate it from the other constituents, and form butter. For making butter the cream should be "ripened," i.e. it should contain certain bacteria. It should then be churned.
On the other hand, if it is desired to beat or whip the cream, but not to form butter, it is necessary to prevent the fat from massing together. To accomplish this, use thick cream (containing 20 per cent or more of fat) from 12 to 24 hours old [Footnote 50: Such cream contains a small amount of lactic acid.] and have it very cold; it will then whip quickly. Cream may be chilled by placing it on ice for some time before whipping or by surrounding it with ice water while whipping. In warm weather, it is safer not only to chill the cream but also to surround it with ice water while whipping.
A harmless substance called viscogen may be added to thinner cream (i.e. the so-called coffee or 16 per cent cream) to make the latter whip. Viscogen is prepared by mixing the following ingredients: