Prepared powders, known as ice cream powders or by some special trade name, are made up for the most part from some of the substances described above. The value of these substances depends upon the presence of finely powdered gum tragacanth or gelatin or a mixture of these in rice flour, powdered arrow root, and sugar. The results obtained from the use of these is sometimes quite satisfactory but on the whole it would seem more desirable for the ice cream maker to know the exact nature and composition of the stabilizer used. City ordinances and state laws are not uniform in regard to the use of stabilizers in ice cream; hence, the importance of knowing the composition of prepared substances such as ice cream powders.

The object of using stabilizers. It seems that the opinion quite commonly held by those unfamiliar with the process of ice cream making is that these stabilizers are adulterants. This, however, is not the case, as these substances are almost analogous to the baking powders or cream of tartar and soda, eggs, and other substances used in cakes to give lightness. In other words, stabilizers are essential to the production of good body and texture in ice cream made under practical commercial conditions. Instead of being adulterants or substitutes for other food products, many of these have a high food value. The food value of eggs is well known to all. The milk solids which are added in the form of milk powder or condensed milk have a high food value also and at the same time improve the flavor of the ice cream.

The effect of stabilizers upon swell has apparently been somewhat overestimated. The opinion held by some is that a stabilizer is used to increase the swell of the ice cream. This opinion is shared by many ice cream makers also, but,

according to all data on this subject available at the present time, stabilizers apparently have just the opposite effect. It has been pointed out that as a rule where varying amounts of these substances are used there is a very noticeable reduction in the average swell of the ice cream during the freezing process.

The use of gelatin in ice cream is frequently denounced not only because some consider it an adulterant but because of the fact that it may become contaminated in the manufacturing process. Since this is quite true of the lower grades, great care should be exercised in selecting the gelatin used in ice cream making. When the proper precautions have been taken to select gelatin of known purity, there can be no reasonable grounds for objecting to its use in the ice cream mixture. The amount used is quite insignificant and instead of being a harmful substance, it is a food of no little value. Although gelatin is not a tissue builder, it is said to have a heat and energy value about equal to that of proteids and is very easily digested. Owing to the fact that gelatin melts very readily in warm water and solidifies again upon cooling, it makes an excellent stabilizer for ice creams and sherbets.

The use of stabilizers in ice creams and sherbets is a matter of considerable importance to the ice cream maker where the product must be shipped or hauled some distance before it reaches the consumer. In the hot summer weather it is difficult to ice a tub thoroughly enough so it will stand a very long shipment unless a stabilizer of some sort has been used. The temperature of the ice cream need rise only a few degrees to bring about a condition in which ice crystals will form when the ice cream is repacked. If the 6 Bulletin 155, Vermont station.

ice cream becomes even slightly softened in transit and is then iced down and frozen, it will be found that the texture has become more or less granular. The difficulties in handling rail shipments of ice cream in hot weather must be encountered to be fully appreciated. These difficulties are overcome, in part at least, by the judicious use of stabilizers.

Just how a stabilizer prevents the formation of ice crystals in ice cream is not definitely known. According to Washburn, gelatin prevents the formation of sharp spines of ice by forming a film around the small ice crystals, and in this way prevents them from increasing in size. He also asserts that gum tragacanth does not form such a film or capsule around the ice crystal but when used in connection with gelatin serves to hold the gelatin capsules together.

The truth of this theory remains to be demonstrated; nevertheless, these substances, which are sometimes called colloids, when properly used, enhance the value of ice cream considerably by giving a better body and finer texture which will not become granular after the ice cream stands for a time.

In nearly all the formulas given in chapters X and XI gelatin only is mentioned as a stabilizer. In these and other formulas other stabilizers or a combination of them may be substituted if so desired.

7 Washburn before the National Association of Ice Cream Manufacturers, Chicago, October 1913.

CHAPTER VI

FLAVORING

Frozen desserts are valued mainly because of their pleasing flavor and their cooling and refreshing effects. This being the case, the commercial value of ice cream depends largely upon the care exercised in selecting suitable flavoring material and upon proper freezing rather than the food value of the products. There are so many kinds of flavoring material which may be used and so many brands and grades that it is necessary to select flavoring substances with great

care.

Spices, sugars, syrups, crushed fruits, fruit juices, extracts and nuts are the flavoring substances used in one way or another in the manufacture of ice creams and ices. Many of these, such as the spices, find but occasional use in the ice cream mixture.

The spices. Cloves, nutmeg, ginger, cinnamon and coffee are the ones most frequently used. Some of these are used only to modify other flavors as in the case of cinnamon, which is often combined with chocolate. Coffee, however, is frequently used as the principal flavoring agent in ice cream and is a popular flavor with some people.

Sugars and syrups serve both as sweetening and flavoring agents. The most important flavoring substances of this class are vanilla sugar, maple sugar and chocolate, maple and caramel syrups.

Vanilla sugar is employed only in the manufacture of certain fancy and cooked creams. The sugar is prepared by pulverizing ten ounces of sugar with an ounce of finely cut vanilla beans and then sifting the mixture to remove the coarse pulp. The seeds of the vanilla bean should be allowed to pass through the sieve with the pulverized sugar.

Maple sugar is one source of maple flavor but is not used to the same extent as maple syrup or maple extract. Chocolate syrup may be prepared by boiling a pound of bitter chocolate, a pound of cocoa and four pounds of sugar with enough water to give a thick syrup. One quart of this syrup is sufficient for ten gallons of ice cream.

Maple syrup is used more frequently than maple sugar as a source of maple flavor. This material is too well known to need discussion here.

Caramel syrup may be obtained ready prepared, or it may be made by melting one pound of refined sugar in a stew pan or frying pan over a moderate fire, gradually increasing the temperature to about 400° F. or until the syrup has a very dark brown color and a bitter taste. When it is in this condition, a pint of water should be added very slowly and boiled until the syrup is as thick as molasses. Care should be taken not to get the syrup too thick or it will crystallize upon cooling. In that case more water must be added and the syrup boiled again.

Fruit flavors may be obtained in the form of a syrup also. These syrups, however, are more for soda fountain purposes and are therefore little used in the ice cream mixture. Crushed fruits and fruit juices are more satisfactory than the fruit syrups as flavoring for ice cream.

Crushed fruits and fruit juices. As a flavoring for ice cream, ices, and sherbets the fresh fruit gives the most sat