BREAD 189 



by rule-of-thumb methods has given place to the modern scientific 

 ones. Brewers' barm has also been discarded. Bakers say that 

 since brewers began to use substitutes for malt and hops, their 

 barm has become too unreliable for regular use. Whether that 

 be strictly true or whether the modern specialised manufacture 

 of yeast has provided an article relatively better need not be 

 discussed. As a matter of fact, compressed distillers' yeast has 

 almost entirely ousted the other forms of yeast. The effects of 

 present importance may be summarised in the statements that 

 the processes of bread-making have been very much shortened ; 

 that modern fermentations approximate more nearly to the 

 desirable pure alcoholic fermentation than olden ones ; that 

 it is possible in a large proportion of cases to use flour, salt, 

 water, and yeast only, dispensing thereby with the use of 

 potatoes and other forms of non-farinaceous yeast food, and 

 that as a consequence bread is less likely to be sour or 

 discoloured by undesirable causes than it ever was. 



One absolute essential for the production of good bread 

 is the use of good flour. It must of course be pure and free 

 from all dirt and contamination — " that goes without saying" — 

 and modern flour complies with those requirements. It should 

 also contain a sufficiency of food available for the yeast plant, 

 and be able to retain when made into dough a large proportion 

 of the gas into which some of its own constituents have been 

 changed by the action of the yeast. The possession of those 

 characteristics mainly constitutes " strength." The loaves pro- 

 duced from such flour are large, and therefore well aerated, 

 probably shapely, and relatively digestible. 



In the April number of The Journal of Agricultural Science 

 there is a most valuable and interesting article by Prof. T. B. 

 Wood, of Cambridge. He has shown from experiments on a 

 considerable number of flours, each produced from a single sort 

 of wheat, that " the size of the loaf depends in the first instance 

 on the amount of sugar contained in the flour together with that 

 formed in the dough by diastatic action." In his summary he 

 also says : 



It is suggested therefore that the difference between strong 

 and weak flours is connected rather with the physical properties of 

 their gluten than with the chemical composition. Since it is well 

 known that the physical properties of proteids are profoundly 

 affected by small quantities of acids, alkalis, and salts, the 



