This section is from the book "A Treatise On Beverages or The Complete Practical Bottler", by Charles Herman Sulz. Also available from Amazon: A Treatise On Beverages.
Preparation Of Fruit-Syrups. - Clarification of Fruit-Syrups. - Preservation of Fruit-Syrups. - Restoration of Fruit-Syrups. - True and Artificial Fruit-Syrups and Adulterations. - Tests for Fruit-Syrups. - Formulae for Natural and Artificial Fruit-Syrups.
In preparing fruit-syrups only refined cane-sugar should be used. After the fruit is pressed out, the sweet or fermented juice strained or filtered, add double the quantity (by weight) of sugar (one pint of juice to two pounds of sugar), heat the mixture a little less than boiling point of water in order to coagulate the albumen, skim, filter and clarify. The albumen coagulates readily at 70° C. (158° F.), and covers all other substances suspended in the solution and is removed by filtering. Boiling of the syrup we do not advise, as it is not necessary, and would only injure the aroma of the juice. Also the fruit-acids present in the fruit-juice convert the sugar into invert-sugar. If fruit-syrups thus prepared are used for delicate beverages, we should advise to store them a short time, as they improve in quality and become better adapted to keep the beverage clear. The conversion into invert-sugar will take place completely, and a clear modification will result, which only could be hastened by boiling the syrup but at the expense of its delicate flavor. Therefore a short storage is preferable.
Another method of preparing fruit-syrups is to use only fermented juices. Either the fresh fruits are pressed out and the juice put aside for fermentation, or the crushed fruits are macerated with some wine and water, and also put aside for fermentation, which will set in quickly and the juice become clarified. Then it is used for preparing fruit-syrups as directed. Fruit-syrups prepared with unfermented juice, seldom give, when mixed with water, a clear solution, and the aroma is not so much developed as is desirable. If fermented juice is employed, the preparation of fruit-syrups will be a little more troublesome; however, a finer product will be the result, yielding a clear solution on the admixture with water. It is not unusual, with some manufacturers, in fact quite customary, to add some artificial fruit essences to fruit-syrups prepared either from unfermented or fermented juice in order to animate the aroma and cause it to be more developed. The fermented juice, prepared as directed later on, will have acquired a rich, harmonious and agreeable aroma, which needs no animation. However, wherever artificial fruit-essences are intended to be added, they should be employed in but trifling quantities. The addition of a small quantity of true fruit-essence, as prepared according to directions given in this work, we highly recommend, as it enhances and enriches the flavor of the fruit syrups.
The directions for preparing fruit-juices, fruit-essences, etc., we give in a separate chapter, later on.
For this purpose it is best to employ either paper-pulp, glass-sand, asbestos or pulverized artificial pumice-stone. All are indifferent to the action of the fruit-acids and do not impair the flavor. The mode of application of these clarifying agents are the same as with plain syrups.
All fruit-syrups should be kept in a cool atmosphere, and if they are properly made, neither fluid nor sugar being in excess, the syrup will keep unchanged for years, as the concentrated syrup itself will act as a preservative. However, to prevent fermentation in certain products the addition of an anti-ferment may prove advisable. Salicylic acid may be used, about eight grains to a quart of syrup, previously dissolved in a little alcohol, or peroxide of hydrogen, about three drachms to a gallon of syrup, Hoffmann's anodyne, spirit of ether, or one of the other preservatives recommended for plain syrups and carbonated beverages.
When salicylic acid is used, the amount of it which enters into a carbonated beverage is so trifling, that no injury to health will result from its use; in this respect we refer to our calculations and opinions expressed under "Preservatives," later on.
In bottling fruit-syrups all the precautions should be observed as recommended for plain syrups.
When fruit-syrups have started fermentation, and restoration by boiling has to be resorted to (see page 627), they are impaired in their properties. The addition of some fruit-juice before boiling, or afterwards of some fruit-essence, will restore their flavor. Then preserve properly again.
Fruit-syrups, made with real fruit-juice, are of course far superior to those made with artificial fruit essences. There is no fictitious flavoring about the former; they have a full, strong fruit flavor.
There are many fruit-juices in the market which are highly diluted with water, but such a fraud will be easily detected; the inferior strength in flavor will prove this. Never follow the directions which assure you that a pint of fruit-juice will make a gallon of syrup satisfactory to every one. Satisfy yourself and your customers, and use enough to give the beverage an agreeable fruity taste.
Genuine fruit-syrups lose their color by chlorine. Those colored with aniline derivatives give at the same time a flocculent precipitate similar to that produced by ammonia in solutions of sexquioxide of iron. Sulphurous acid destroys the color of both; sulphuric, hydrochloric, and nitric acids render the color of genuine syrups brighter, and change the artificial ones into yellowish-orange. Potassa decolorizes fuchsine syrups, while red fruit-syrups acquire a dirty greenish hue. Carbonate of potash does not change the color of artificial syrups, while the others are colored green. Basic acetate of lead gives with real fruit-syrups a greenish precipitate, with fuchsine syrups a red one.
Properly speaking, the formulae for making natural and artificial fruit-syrups belong under the caption of "Compound Syrups," to which we refer the reader.