FoodNet

Twenty lessons in domestic science

1916

Page 14

Presented as published in 1916. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
Tartaric acid is manufactured from Argol, which is the sediment that separates out at the bottom of the, wine vat during the fermenta- tion. This substance is colored by the color from the grapes, and is a mixture of tartaric acid, calcium tartrate, cream of .tartar and all kinds of organic impurities. This mixture is» dissolved in water, precipitated with powdered chalk and calcium chloride, filtered and then the precipi- tated calcium tartrate is dissolved in sulphuric acid. This solution is again filtered and treated with some decolorizing agent, such as bone black or infusorial earth, and the subsequent clear, colorless solution evaporated and the tartaric acid allowed to crystallize. Cream of tartar is also obtained from the same sediment, Argol.. It is decolorized by heating with animal charcoal, filtered and recrystallized. Acid Phosphate Calcium Acid Phosphate is prepared from the same source as is much of the "Phosphate," used at soda fountains. The bones from healthy cattle are heated in large revolving cylinders until they are thoroughly charred. In this condition the mass is black and is known as bone black, although in/reality it consists of both calcium phosphate and charcoal. This substance is use^d to decolorize the juices of the cane in the manufacture of cane sugar. In the manufacture of phosphate It is again heated to a very high temperature whereby all charcoal is burned off and only the calcium phosphate remains. It is then further purified, concentrated, crystallized and dried to a white powder. A more recent process is the manufacture of phosphate for food purposes from phosphate rock. This material was not formerly used on account of the great difficulty -of excluding from the finished acid (phosphate the harmful impurities, fluorides, always found in the rock. Bone phosphate is the better on this account and is always used by the careful manufacturer of high grade baking pOwder. Calcium acid phosphate for baking powder is prepared in two degrees of fineness, powdered and granular. The granular (the acid phosphate as found in Calumet Baking Powder is of the granular type) jis much more expensive but has the great advantage of making a baking powder that will keep longer than one made from powdered phosphate. "Alum" The so-called "Alum" used in baking powder is not the alum which jis sold at the drug store by that name. The common alum of trade, iwhich is also used as medicine, contains potassium, an element that is !toxic in very small quantities, and water of crystallization ; it is, in fact, , 34 Domestic Science LESSON No. 2