The boiling of the wort in these three huge coppers is another one of the essential phases of brewing. The heat required for the boiling is furnished by boilers which send a continuous current of steam through the coils fixed in the copper. These coppers have covers with small sliding doors, which, during the process of boiling, are rarely opened except to enable the brew-master to make his tests. Were it not for these covers, the boiler-room would be enveloped in an impenetrable cloud of steam, which would greatly hamper all manipulations. As it is, the steam finds an outlet through a large pipe or flue fixed on top of the copper. It is at this stage that the hop is added to the wort, but not until after the latter has boiled a sufficient time. Usually, the boiling requires four hours; at the expiration of the third hour, or still later, perhaps, the brewer will empty the contents of several large sacks full of aromatic hops into the copper, thus adding the bitter principle to the saccharine. The proper treatment of the hops at and during this stage always has been a matter concerning which few brewers shared the same opinion; but of late scientific investigations have removed many prejudices which arose from a misconception of the nature, ingredients and functions of the plant. At present, the average brewer fully understands that he can extract the essence of the hops without excessive boiling. The object of the boiling is: 1. To concentrate the wort; 2. To extract the essence of the hop; 3. To coagulate the unchanged albuminous substances and cause them to settle, together with the unconverted starch which, if allowed to remain intact, would materially militate against the preservation of the beer. But this does not do justice to the important function of hops; at least it is to be feared that, to the average reader, it will not convey a clear idea of the action of this tender plant upon the wort. Without it, beer would be nothing more than fermented barley-juice, which, as we have seen, was known to the most ancient nations. Without it, beer could not be preserved for any length of time, and both in appearance and flavor would be greatly inferior to the drink of to-day. Hence, hops not only impart to beers their pleasantly bitter and aromatic flavor, but they also assist in clarification and produce the preservative qualities of the liquid. The two principal substances which the hop-cone yields when boiled, are lupulin and tannin, and it must be the brewer’s aim to extract these in just that proportion which the condition and quality of his wort require. Injudicious handling of the hops may result in an excess of tannin and a deficiency of lupulin, and may otherwise work injury to the finished product. The diminutive sparkling grains of the hop-flower, called lupulin, are closely wrapped up in the center of the hop-cone, and should be laid bare before the plant is placed in the copper. To this end most brewers break up the