isa-normaladvance-1909-00208

Description:	208THE NORMAL ADVANCEI will write some time next year of mywanderings and life in Europe. I do not yetknow the order of my stay in the differentcities, but will study in Paris with Clark andMarches!, in Florence with Lombardi, in Berlin with Lilli Lehmann and in London withShakspere. I expect also to be in Rome andMadrid, but as I said before, cannot know myexact schedule, as yet.Au revoir for a short while, for I will be inIndiana and probably visit the old I. S. N. before this is in print.LELLA PARR.April 6, 1909. New York.SCIENCE DEPARTMENTBaking PowdersRAYMOND JAREDIt is surprising to notice and to know howmany of the common things about us in ourhomes and our business, are based upon chemistry and chemical reactions. The fact thatwashing ones hands cleanses them, is based ona complex chemical action. Many other littlethings could likewise be pointed out. Especially in the kitchen, in the art of cooking, arechemical principles made use of. It is necessary, in baking bread, cakes and biscuits, tohave an aerating agent, or in other words,something to raise the bread. There are various methods, in use, of doing this in generalone must have a gas, either already formed andthen introduced by some mechanical means, orto be evolved in the dough itself by chemicalreactions taking place. In this latter case onemust have an acid to liberate the carbon dioxide, also one must have a carbonate to furnish the gas.The most universal source of carbon dioxideof leavening bodies is sodium bi-carbonate. Theease with which it gives up the gas and thelarge percentage of it available makes it ofhigh value for this purpose. Among the simplest acid agents used is lactic acid which ispresent in sour milk. By mixing togethersodium bi-carbonate, sour milk and flour, thehousewife has a very cheap and active leavening agent and one which has very extended usein the country. One of the most serious objections to this method is that any undecomposedparticles of sodium bi-carbonate tend fo stunthe flour and to give a very unpleasant taste.Rolls, when made in this way, therefore, whendone, often, instead of being white or creamcolor, have yellow spots, which are objectionable to the eye, and also give them a very disagreeable taste. It is not possible in any givencase for the house-wife to judge accurately theamount of sour milk and soda to use. Becauseof the fact that sour milk is not available tomany people since they moved to town, and alsomany other uses of milk, more important thanformerly, have been found, a demand for someartificial product to take the place of this oldmaterial has come up. To meet this demandand also to remedy the objections stated above,leavening agents have been produced which areprepared by balanced chemical formulas insuch a manner as to give complete re-actionduring process of baking, whereby the totalavailable carbon dioxide is secured in a gaseous form and residues are secured in which nolonger remain alkaline enough to stain or makea disagreeable taste in the bread.Baking powders may be classified into threeclasses according to the acid constituent theycontain, (1). Tartrate powders, in which theacid is tartaric acid in some form. (2). Phosphate powders, in which the acid properties arefurnished by phosphoric. (3). Alum powdersin which the acid constituent is sulphuric acidin some form of an alum salt. All powdersnow sold will come under one of these threeclasses although there are some powders which
Source:	http://indstate.contentdm.oclc.org/cdm/ref/collection/isuarchive/id/34238
Collection:	Indiana State University Archives

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