Potato flour is a yeast food. It contains gelatinized starch, sugar, dextim amides and mineral matter, all of the bodies are yeast nutrients, the first-named being converted into sugar by a ferment in the yeast. The analysis of pure imported potato flour should approximately show as follows: Water, 10.69 per cent.; protein, 6.59 per cent; fat, 0.23 per cent; nutritious extractive matter, 78.73 per cent; fibre, 1.18 per cent; ash, 2.58 per cent, making in all a total of 100 per cent.

The extractive matter is mostly carbo-hydrates (sugar). The ash, the mineral matter, mostly phosphates.

We have here three important bodies for yeast production—carbo-hydrates, protein and phosphates, and the last two, moreover, act as powerful stimulants. Owing to these facts, the writer thinks a closer acquaintance about the use of potato flour will be of some interest to the progressive bread baker.

It is often said that formerly, before the introduction of compressed yeast, when potato ferments were mostly used, that bread was superior in flavor and keeping qualities than most of the bread baked at present.

Furthermore, bakers of to-day find it absolutely necessary to add large quantities of sugar, lard and often milk to their dough to overcome the effect that compressed yeast has brought about. It is not the writer’s intention to belittle the value of compressed yeast, as this product is now an inseparable commodity in the bakeshop.

It is, however, possible to get back the advantages obtained from the old potato ferment process by the judicious use of pure potato flour.

It eliminates entirely the old cumbersome method of boiling and mashing potatoes, scalding flour and setting away the ferment until ready for use, for five or six hours. Pure potato flour used in connection with a small quantity of diastasic malt extract will accomplish results gratifying to the baker and assist in cutting down cost of production.

In the first place, the diastasic power of the malt extracts converts the carbo-hydrates of the potato flour into maltose, and if this is carried in far enough produces more than enough saccharine matter for any dough. Secondly, the extractive and mineral matter of potato flour gives great assistance to the raising properties of yeast by stimulating and increasing yeast cells in a medium befitting their propagation according to the laws of nature. While this may seem clear in theory, any baker can easily ascertain the above bespoken values of potato flour by practical tests. The following formula will be sufficient to guide the baker to make any size test he contemplates to make for a straight dough: 1 qt. water, .08 oz. malt extract, 1 oz. potato flour, .75 oz. lard, 1 oz. salt, .33 oz. yeast, 3 lb. 5 oz. spring patent flour. For a barrel of flour this would equal 15 gals. water, 7 oz. malt extract, 3¾ lbs. potato flour, 3 lbs. lard, 3½ lbs. salt, 1¼ lbs. yeast, 196 lbs. flour.

Weigh the potato flour into a clean tub, pour 4 gals. of water, at 90 degrees F., in, also the 7 oz. of malt extract, and mix up; then break into it the yeast and see to it that it is all dissolved. Cover up with a clean bag. Now get all your other ingredients into the mixer or trough, the balance of the water, your salt and lard scaled off, and your barrel of flour ready. By this time your ferment in the tub will have risen, and be on the point of falling. It is then ready to mix all together and dough. The water should be tempered so as to bring the dough out between 82 and 85 degrees F.

Mix the dough well until clear. Allow it to stand and give it full proof before knocking down first time, which will take about 3½ hours. When it has come up again about three-quarters proof knock down again. Give it another one-half proof in the trough and your dough should be ready to take; in all, 5½ to 6 hours. You will find that potato flour makes your bread keep moist. It will give a rich nutty flavor and will give a much larger yield on account of its moisture, absorbing qualities, and on the whole make a very satisfactory loaf. This, in the writer’s estimation, is the best way to use potato flour in order to get best results at lowest cost of production.

Potato flour may be used dry. When making straight dough this way the potato flour must always be sifted into the flour dry. The quantity to use varies according to strength of the flour and the baker’s own ideas, say 4 to 6 pounds for each barrel of flour. Without changing your usual formula, except cutting some of sugar and increasing water, it will produce good bread.

If the potato flour is scalded and then cooled before using it will assist such as want to get a solid home-made loaf.

No other ingredient, to the writer’s knowledge, will produce bread that will compare in flavor and texture with the old style potato ferment bread than when employing pure imported potato flour judiciously, according to any of the above methods described, nor can any bread be made, considering quality, cheaper or as cheap.