% B A K I N G P O W D E R . A Healthf u l Con ven i en t Leaven i n , g Agen t B y T A A G TK I B c . M S . H O S N SON . , M D ( Lond . ) o es so o f s o o J en n e M e ca o e e ca o Pr f r Phy i l gy, r di l C ll g , Chi g , Illin o is ; F o rm erly Pro fe ss o r o f Phys iolo gy a n d s o o c a e st c a o o e e o f Phy i l gi l Ch mi ry, Chi g C ll g M e c n e a n d e a n d i n th e e c a n di i Surg ry , Am ri a o L o s M o M e c e e S t. ss di l C ll g , ui , i uri . S ta ff E dito r A meri c a n J o u rn a l of Cli n i c a M di c i n l e e . T H E COMMONWE AL TH P R E SS P u blis h ers of S c hool B ook s C H C G I L L I N OI S I A O , C O P YR I G H T 1 9 1 5 M . S e . B , . D E M . (at T AB L E OF CON TENTS A CH PTER I . Introduction L A n ta s o f i n A n i sa a n ta e s o f Ye a s t . a e e a ven g ge ts . D dv g dv g i n e s S o ce s o f a on i o i . Ba k g Powd r . ur C rb D x d A s 3 - 1 3 CH PTER II . The Ingredient of Baking Powder A n m n i a te . M a n s i a o n a o a o e a te . S o d . m um C rb g um C rb ' s n T A i S s t n a i h e c a c . a t c Other Sub ta ce s N ece s sa ry . d ub e T r r % % A n a t A i A m i a e a o f a c o s a te . c d d Cr m T r r . d Ph ph lu ta W te o f s . S rch . hi Egg - 2 A . 1 4 6 CH PTER III Choice of an Acid Ingredient . A n ff n i n i A n ca ti o . ppa re t Di ere ce i n Ba k g Powd ers . Chem l c A n f Ga s S et F e Th e A ou n t of th e e s i s Th o e . e mou t r e . m R du K e e i n a i i f t e s . ee o Hea lthfuln es s of th e R e si du e s . p g %u l Sp d A n ro e a a n ce ti o n . Acti o . P p rly B l d c A I a Use 135k CH PTER V . The M nufacture and of ing Powder 27 - 33 i M a n a ct i n A i a n ce s Th e Us e o f a n o e . uf ur g ppl . B k g P wd r H M i n o e - i si n a s . a S o w to e ure Ca re o f B k g P wder . lf R g F lour . i CHA PTER V . The Determ nation of Available Carbon Dioxid 35 - 39 ’ H i n s M A so ti on M t o e . a rr s o etho d . b rp h d A o s - 4 1 CH PTER VI . C nclu ion 4 0 o s t of a n o e a i n o e a N e e s si t C B ki g P wd r . B k g P wd r c y . Answers Appendix oto a i c e o ti on f eti n N O 1 03 Un i te c o . S ta te s Ph gr ph r pr du Bull , d e a t en t of A i c t e o n t i ti on o th e e e e e D p r m gr ul ur , C r bu fr m R f r i n i fi e t I oa o f on s ti n S c e t c s . ra e sen B rd C ul g Exp r R m , a i a n Ch rm . 887 3 4 3 ‘ D omes z i e Scien ce Text B ook age 1 CHAPTER I L aE A VE N I N G AGENT S HE common leavening agents in u se in the home Y s i s are yea st and bak ing powder . ea t a mi s i ss cro cop c plant which , in the leavening proce , produces changes which finally resul t i n the breaking u p of sugars into alcohol and carbon dioxid ga s . B aking Powder i s a mixture of several sub stances which produce thi s same ga s by chemical action . This a s b - s s g , y forming in mall bubble throughout the dough a a s i s ss s s . ma , lighten or leaven it C rbon dioxid g p s a s i s a s ometimes called carbonic acid g s . Thi the g i i o s h s s r , h h r w ch pre ent in all carb nated wate ‘ w et e a s s u s . natural or artificial , in oda fo ntain water DI SADVANTAGE S OF YEAST s s i s N the ca e of yea t , the fermentation wh ch produce a s i s s a s ff the g never of a ingle kind , many di erent m i s fer entations are going on at the same time . It ss s ff impo ible , commercially, to control the e di erent fermen tati on s so that they will always exi st i n the same s a s ff proportion ; hence , we find that the fl vor from di er ent bakings vary grea tly and are sometime s obj ecti on . s u s s able Moreover, everal ho r mu t be allowed for the process of fermentation before the food can be placed in the oven . Fermentation does not take place readily s a a s in the pre ence of l rge qu ntitie of butter, lard or s egg . Pa ge 2 D o mes tic Scien ce Te xt B o o k ADVANTAGE S O F BAKING POWDER a ITH a properly compounded b king powder , i on the other hand , the chemical reaction w ll s s alway be the ame , and any influence which it may exert upon the flavors of the fini shed food will always s a ha s s be the ame . B king powder , moreover , the e two further advantage s over yea st :The ga s i s given o ff at once upon the addition of water or in the oven during the i s heating ; there s no waiting . And the pre ence of but s s . ter , lard or egg doe not hinder the chemical action s i s s The leavening , from whichever ource , alway s l s a s the re u t of the ame g , carbon dioxid , and in the study of baking powder we are intere sted in learning how thi s ga s i s produced by chemical action . SOURCE S OF CARB ON DIO% ID ARBON dioxid i s found in nature combined s s chemically with many metal , and the e combina s as s s tion are known alt of carbonic acid , or more s i i i s commo nly a s ca rbonate s . Tho e w th wh ch one s s mo t familiar are chalk , marble and lime tone , all of which are diff erent forms of calcium carbonate . If s any of the e are heated to a very high temperature , carbon dioxid ga s i s set free and lime remains ; but thi s very high temperature i s never reached in baking . Baking soda i s another carbonate with which all are i famil ar . D omes tic Scien ce Text B o o%e Page 3 CHA PTER I I THE INGREDIENT S OF BAKING POWDER SODA ODA i s the carbonate which i s used at home for cooking pur po se s ; it i s al so commonly known a s i s d s s s . s s aleratu , or baking oda Thi the carbonate u e almo st exclusively in the manufacture of baking pow n i s s der a d always named on the label a s soda .