"The new brewery is of the most complete character, the machinery and utensils in connection with it being of the best and most improved kind, and some of the vessels of enormous capacity. Ascending a flight of steps, we came to the mash room, a lofty apartment 52 feet by 36 feet, well-lighted and ventilated, the floor of which is both fire and waterproof. It contains five mash tubs, each capable of mashing fifty-five quarters of malt, four of which are fitted with Steels mashing machines, and the other with the old-fashioned stirring rakes, and all possess perforated copper false bottoms. The operation of "mashing" is an important one, and the greatest possible care has to be taken by the brewer, that the water to be used is of the proper temperature, and at no time during the process is his art put to a more severe test than at this period, After the wort has remained in these vessels the requisite time, it is drawn off the underbacks, of which there are two below the floor, both constructed of copper ; these are merely temporary receptacles for the wort, which runs therefrom direct to the coppers. Crossing a timber bridge, stretched over the hopbacks, we reached the copper house, a large place 60 feet square, with glazed roof and side lights. Here we were shown seven large coppers by Briggs and Morton, in each of which eighty barrels, or 2,880 gallons of wort is boiled with the hops at one time. Boiling is continued in these vessels for some hours, after which the hops are separated from the wort, and subsequently pressed under hydraulic presses. On our way thither we noticed, from the bridge, the two copper hop backs, each holding 170 barrels, where this separation takes place, and which is accomplished by draining the wort through gun-metal strainers.
In the copper house we also noticed Daniel's patent apparatus for condensing the washings obtained from the hops after the wort has been drained from them The process was explained to us by our guide as follows :—After separation from the wort, the hops are allowed to remain in the circular hop-back, and over them the necessary quantity of hot water is sparged, until all the saccharine matter they hold is completely washed out of them. These washings are then drawn into the apparatus and very quickly evaporated to the required gravity ; after which, they are pumped up to the coolers, and then mixed with the brew to which they originally belonged. The great advantages of this process are the rapidity of the evaporation, and the avoidance of anything like decomposition or colour in the wort, these ends being obtained by boiling the liquor in a vacuum at a low temperature. The process has been in operation in this brewery for several years with most satisfactory results.
From the copper-house we ascended to the cooler-loft, which forms the roof of next building, and measures go feet by 63 feet.
It contains one of Briggs and Co.'s copper coolers, 44 feet long, 28 feet wide, and 12 inches deep, with a capacity of 200 barrels, and three of Morton's horizontal refrigerators; but the greater part of the floor is covered with four open shallow coolers, wherein the cooling process commences ; the wort then runs over the refrigerators into the fermenting squares placed on the floor below. We noticed a novelty in this cooling room, consisting of two dreg filters - the first we had seen of that description in any brewery - being square timber vessels used for filtering the grounds which are left behind in the coolers, by atmospheric pressure.
"Noted Breweries of Great Britain and Ireland, vol. 2", Alfred Barnard, 1889, pages 119 - 122.
Five mash tuns, each with a capacity of 55 quarters. Assuming their Pale Ale had an OG of 1065 and they were getting an extract of 85 brewers pounds per quarter, I make that about 200 barrels of beer per mash tun. Or, in total, about 1,000 barrels a day. That's quite a lot of beer. The annual capacity would have been 250,000 - 300,000 barrels. Not quite on the same scale as Bass or Guinness (who each brewed around 1 million barrels), but enough to put them in the top twenty. I'm sure I've got a league table of brewers somewhere. Here it is: