In use the body of the apparatus is partly filled with water and the material to be treated. This is acted upon by a steam pressure of two atmospheres, which is later increased to three, steam entering by the lowermost pipe, passing up through the water and potatoes thoroughly agitating the same and passing away by the steam gauge. After standing at the last pressure for ten or fifteen minutes the lower steam inlet is closed; the upper inlet and the blow-out valve are opened. The steam is then increased to its highest point or about four atmospheres and the lower valve is opened. The disintegrated material is forced out by the steam through the grating at the bottom of the cone. This comminutes it and pulps it before it passes into the preparatory mash tub. Blowing out requires about 40 to 50 minutes. Steaming and blowing out together cover a space of two hours. The pressure of the steam before blowing out should be such that the steam is constantly being blown off through the safety valve. Thus the mass in the steamer is agitated and the material entirely disintegrated and gelatinized. =Process.= Into these apparatuses the potatoes and corn or grain first ground into mash, or even corn or grain unground, if the pressure is high enough, are disintegrated and cooked by steam under high pressure. During this process the starch becomes partially dissolved and partially gelatinized, which occurs when a pressure of some 65 pounds has been attained, with a temperature of about 300∞ F. =Saccharifying.= It is now necessary to saccharify the gelatinized mass. This is accomplished by adding to it a certain amount of malt, whereby maltose or sugar is formed through the action of the diastase. The amount of maltose so created is in proportion to the amount of malt used, the length of time it is acting, the dilution of the mash, and the existence of a proper temperature. The temperature best fitted for this action lies above 122∞ F., but in order to entirely dissolve the starch a temperature of 145∞ F. should be used. In addition, at this higher temperature, the bacteria inimical to fermentation are destroyed. A higher temperature than 145∞ F. should not be allowed, except in extraordinary cases as it injures the effectiveness of the diastase. =Apparatus.= The mixture of the malt with the mash may either take place in the heater and cooker itself (see Fig. 2) or in a preparatory mash vat. In the first instance, the malt is allowed to enter the cooking cylinder when the temperature of the mash is about 145∞ F. The mash is stirred until thoroughly mixed when the product is drawn into a receptacle called a drop tub and later reduced to a proper fermenting temperature. When the Henze type of steamer is used, the pulped mass (see Page 121) is blown into a preparatory mash vat, at the proper temperature. It is left to stand at this temperature for a period varying from twenty minutes to an hour and a half.