The mash is now heated with steam and hot water, in 15 to 20 minutes, to 59° R. (165° F.) and the stirrer stopped. The mash is now al lowed to rest from 30 minutes to one hour in order to allow the hulls of the malt to settle so as to act as a filtering material for the wort, after which the wort is run into the kettle. After the wort has run off, the solid substances remaining in the mash tub, called grains, are washed out or sparged with water in order to recover as much of the wort contained in them as possible. The grains are then thrown out of the mash tub and sold as cattle feed.
Boiling the Wort in The kettle consists of a pear-shaped copper vessel having a double or jacketed bottom for heating the wort, and a vent pipe to roof for conducting off the vapors generated during boiling. The steam outlet of the coil or jacketed bottom is con nected to a steam trap which automatically dis charges the water condensed in the coil or jacket without materially reducing the pressure of the steam. The wort as soon as it runs clear from the mash tub is collected in the kettle.
the wort between these lumps clear and trans parent. This clarification is called the ((break ing') of the wort.
Hops are now added, usually about two fifths of the total amount used, after which addition the wort again becomes turbid due to the further precipitation of albuminoids by the tannic acid contained in the hops. After about 40 minutes further boiling the wort should again clarify or show its second break, when another two-fifths of the hops are added and the wort boiled about 20 minutes. The remaining one fifth of the hops is added and the wort run out of the kettle into hop jack immediately. This last quantity of hops is usually of a better quality and is not boiled with the wort as its addition is for the purpose of imparting the hop aroma to the wort. This aroma is due to the hop oil of the hops which is volatile at boil ing temperature and would escape, and be ren dered useless, if the wort were boiled for any considerable time. All or part of this last hop addition is sometimes placed in the hop jack and the boiling wort run upon it.
Wort in Hop hop jack con sists of a round or square iron tank, having a perforated false bottom or strainer and a sparger or sprinkler similar to that of the mash tub. The wort, with the hops, is run into the hop jack and allowed to rest until the hops have settled so as to form a filtering material for the clarification of the wort. As soon as this takes place the wort is pumped to the sur face cooler or beer tank located at the top of the cellars. After the wort has all been re moved the hops are washed out or sparged with hot water in order to recover as much of the absorbed wort as possible.
Surface Cooler and Beer Tank.— The sur face cooler consists of a shallow iron pan of a length and width very large in proportion to its depth so as to give the wort as much surface as possible. Hereby the wort is cooled quite
rapidly and aerated.
The beer tank, an iron cylindrical vessel, closed at the top, is rapidly supplanting this cooler, since the latter, by the large surface it presents, exposes the wort to infections by impurities or germs always more or less pres ent in the air. As soon as the wort on the sur face cooler or in the beer tank cools to about 50° R. (145° F.) the danger of its infection by impurities, bacteria, etc., begins. From this stage until the beer is finally marketed, months later, it requires the daily, almost hourly, vigi lance of the brewer to keep it pure and free from contamination.
Baudelot Cooler.— This consists of a series of pipes or tubes arranged in vertical tiers, over the outside of which the wort flows, while through them the cooling medium is circulated. It is usually made in two sections, the upper being of copper tubes, containing cold water, and the lower of steel containing ammonia.
The Cellars.— The wort after cooling enters the cellars, where it is fermented, stored, kraeusened, bunged, fined, filtered and racked ready for the market.
Fermentation of Wort.— The wort as it comes from the cooler is run into fermenting tubs in which the yeast has previously been placed. Sometimes the yeast is added after the tubs are filled with wort. The yeast, from one to one and a half pounds to the barrel of wort, is usually given, not in its natural state, but first mixed with an equal quantity of wort and thor oughly aerated.
The fermentation now begini Within 15 to 24 hours white bubbles appear on the surface around the sides of the tub. The wort at this time is covered with a head of thick, lumpy consistency composed largely of albuminoid matter. The whole surface now soon becomes covered with a fine white froth, which soon changes to a frizzled appearance called ukraeu seri') stage. The froth head then moves toward the centre, the fermentation becomes more active, the froth head rises higher and becomes darker and the fermentation now passes into the Thigh kraeuseno stage, generally after about 70 to SO hours. This stage is maintained for about 48 to 72 hours when the head begins to rnllanse and deepens in color to the end of the Storage of Beer.— After the wort is fer mented the beer is filled into storage vats (closed at the top) where it is stored at a tem perature near the freezing point for about two or three months. During this storage period there is a slight progress of secondary or after fermentation and the yeast settles, and, what is most important in bottle beer that is to be pas teurized, there is a further precipitation of albuminoids.