Take three quarts of wheat bran, and boil in two successive waters for ten minutes, each time straining through a sieve. Then wash it well with cold water in the sieve until the water runs off perfectly clear; squeeze the bran in a cloth until dry, spread it in a granite baking pan and dry it in a slow oven. A very good way is to put it in the oven at night, allowing it to remain until the morning. The oven must be sufficiently hot to dry the bran or it will ferment. When perfectly dry and crisp grind it through a coffee mill and sift through a fine hair sieve. If any portion of the bran is retained in the sieve put it back and grind it over. Put the flour thus produced in glass jars and stand aside for use.