The first extract, before it is blended with hops, may be estimated to be nearly as strong as a first wort of common small beer. This, when under a strong ebullition, raised the thermometer to 216 degrees, and seven barrels of such a wort, when boiling, occupied an equal space with nine barrels of cold water, at the mean temperature of 60 degrees. Now, if the degrees of expansion follow the proportion of those of heat, the following table, constructed upon this supposition, will shew how many barrels of cold water would be necessary to occupy the same space with seven barrels of wort of different heats. Degrees of heat. Barrels of cold water. Barrels of wort. 216 9,00 7 206 8,87 7 196 8,75 7 186 8,62 7 177 8,50 7 167 8,37 7 158 8,25 7 148 8,12 7 138 8,00 7 127 7,87 7 119 7,75 7 The quantity of water evaporated in a brewing, when not in immediate contact with fire, is more considerable than it is generally apprehended to be; after repeated trials, I have found that what was lost in this manner amounted nearly to one fifth. Now since the heat of the first tap was 138 degrees, and my mash tun holds 20,25 gallons upon an inch, the following proportion may be deduced from the preceding table. If 8------------7----------------20,25 7,00 -------- 8,00) 141,7500 -------- 17,71 Gallons, and this is the true quantity contained in one inch, at a heat of 138 degrees. The quantity of water used for the first mash, was 12B. 2F. 3G. or 428 gallons, of which one fifth is supposed to be steamed away, when the first liquor is gone through the whole process of the extraction: but as the gauges of the malt and water together are taken before the tap is set, in the beginning of the process, the whole evaporation ought not to be deduced, and one sixth seems to be a sufficient allowance on this account. We may therefore suppose 357 gallons to be in the mash tun at the time of gauging, which number being divided by 17,71, will shew how many inches are taken up by the water at that heat. 17,71)357,0000(20,15 3542 -------- 2800 1771 -------- 10290 8855 -------- 1435