THE BAKERS GUIDE

with the aid of this zymase, digests the food it obtains from the flour, uses some of it (very little) for the purposes of build* ing up its own structure, and some of it for respiratory oxygen ; and then having used and changed its food, yeast give9 offf respires, excretes, as waste, a gas called carbon dioxide and alcohol. Naturally it follows that one cell, like one man, can only do the work of one cell, and live the life of one cell. And light bread is not the result of a ferment or a sponge, but of a sufficient number of yeast cells to do the work. Nor is the counting of them a difficult matter, it is as easy as to say one horse will draw a ton, and if I have a io-ton load I shall want 10 horses for it. We require 960 c.c. — by measure— of this gas to aerate every pound of flour in the batch, and if it is a one-sack batch we shall require 300,000 cells of yeast to aerate this batch with gas, and it will take then quite 6 hours' time to do it. In that time the first 300,000 will have quadrupled, and more — that is to say, it will take a million and more cells of yeast to raise one sack of flour in a given time, and, thereforef there is no question of ferment, sponge, or any other process, but simply a question of the quantity of yeast that is used. To go back to that one horse and one ton, suppose you have only one horse and have 10 tons of stuff to move one mile, what do you do ? why, move a ton at a time, and of course, occupy the time of 10 journeys instead of one. If you use Scotch flour, Parisian or compound barms, you have got a one- horse show, and you must give this one horse plenty of time in which to do the work, and the few yeast cells in these

There are the hydrolysing agents, the enzymes, and dias- tasis at work. There are the putryfactive and the acid-making agents at work, for most if not all of these are present, especially in the more common sorts of flour. With the aid of the water these enzymes are breaking down and changing the albuminoids, and the acid-making germs are present of a certainty in every dough, and it is only the addition of large doses of salt (read the uses of salt) in long processes which permits bread being even eatable, for all the beautiful aromatic and sugary flavouf have either been destroyed or evaporated.