BEER 309 



upon a lino with the surface of the liquid, it indicates that a barrel of that wort weighs 

 ten pounds more than a barrel of water. See SACCHAKOMETER. 



Or, supposing the barrel of wort weighs 396 Ibs., to convert that number into 

 specific gravity, we have the following simple rule : 



360 : 396:: 100 : 1-100 ; 



at which density the wort contains about 25 per cent, of solid extract. 



Now the ordinary German chemical thermometer, as supplied from all laboratories 

 is by far the more reliable and useful instrument ; some men have for years used them 

 in the mashing, and are quite proud of the exactness and facility with which they are 

 enabled thereby to manage the process. The hair stem is enclosed along with a paper 

 scale (properly adjusted and accurately divided) within a glass tube annealed at the 

 top, and the lower end on to the upper portion of the bulb ; thus, with certainty, ex- 

 posing the bulb alone to the influence of apparent heat. By fine copper wire twisted 

 round the top and lower portions, this tube is attached to a long wood stick 1 inch 

 x 1-J, cheeked on either side with a lath of 3 or 4 feet long, and rising to the 

 front nearly of an inch, to protect the thermometer from actual contact in the 

 event of an accidental knock ; upon the lower end of the stick I attach a small tin 

 box or cover about 4 inches long, just the width of the stick, and about an inch in 

 depth. This covers the bulb, and is fitted at the lower end with a simple tin trap- 

 door valve arrangement, which opens upward on the inside, whenever the slightest 

 pressure is applied underneath it by contact with the mash, and the instrument is 

 complete. 



When this apparatus is thrust into the goods, their upward pressiire pushes open 

 the valve, and allows them to pass over the bulb, and immediately on attempting to 

 withdraw the instrument the valve again closes. This of course can be repeated at 

 pleasure, and changes the goods in immediate contact with the bulb, with every fresh 

 motion of the hand, be it ever so slight, and these are distinctly marked by the click 

 of the valve as it closes being felt. By this simple and inexpensive arrangement, the 

 brewer has a trusty, useful thermometer, with which he can easily obtain a sample of 

 his mash from any part of his tub whatever. The thermometer can bo read with the 

 greatest deliberation ; its indications are almost instantaneous and quite reliable, and a 

 slight jerk is all that is required to free it entirely from every grain the box contains, 

 when reading the stem. 



We will here give a few moments' consideration to the amount of extract to bo ob- 

 tained from a certain quantity of malt, and for practical purposes let us say eight 

 bushels, or one imperial quarter. 



It is ascertained from experiment that, on an average, 60 Ibs. of ordinary glucose 

 (grape-sugar) are equal to 2 bushels of malt in producing a barrel of beer. A bushel 

 of malt usually weighs about 40 Ibs. ; if it weighs less, on account of being more 

 thoroughly malted, it is all the better. This proves that 80 Ibs. of dry malt, at least 

 60 Ibs., or 75 per cent., are taken up by the brewing liquor. It has been further ascer- 

 tained by experiment that the amount of those substances just given, namely 60 Ibs. 

 of glucose, or 80 Ibs. of malt, will produce a barrel of beer of 20 Ibs. per barrel 

 gravity. 



From this the practical brewer may deduce that, to ascertain the amount of dry extract 

 taken from the malt ho has been brewing, he must multiply the Ibs. per barrel gravity 

 by 3, and even this will but show the proportion of dry extract taken up by the 

 brewing liquor alone. This multiplier is somewhat more than that allowed by the 

 Excise, theirs being 2'6 instead of 3 ; but it must be borne in mind that their Tables 

 were framed upon the basis of cane-sugar instead of malt, and that 90 parts cane- 

 sugar are equal in atomic equivalent to 95 parts pure glucose. On this account, there- 

 fore, also, their multiplier ought to be 27368 instead of 2'6. The knowledge of this 

 is of course extremely galling to the export brewer. It will at once be seen that, in 

 order to determine by a rough and ready estimate what a certain amount of malt 

 should produce, simply divide the total number of Ibs. of malt by 4. This will give 

 the total gravity of extract obtainable from good malt for common beers, and if it is 

 desired to know the Ibs. per barrel that should be obtained for a particular brewing, 

 simply divide this total extract gravity by the number of barrels brewed; thus 

 20 quarters of malt at 40 Ibs. per bushel = 6,400 Ibs. malt : 



4) 6400 



1600 Ibs. gravity of extract. 



When cooled down and got into the fermenting-tun, if there were 60 brtrrels of it, 

 1600 -*-66 = 24'2 Ibs. per barrel, would be the weight of the beer. This is found 

 practically correct, though it must not be contended that you have hero an account 



