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THE PRACTICE OF FERMENTATION : IN ENGLAND. 
with the ends folded over. Several of these cloths are placed over each other, a dozen 
or more at a time, and are all pressed together. In Devonshire, successive layers of reeds, 
or of fresh drawn clean straw, are often used in the press instead of the horse-hair cloths. 
The press is precisely similar in principle to that used for making cheese, but its machinery 
of late years has been considerably improved; and, indeed, the whole process of what is 
technically called “ making the cheese ” simplified and accelerated. Pressure should be 
made very gradually at first; for the juice which first exudes is turbid, and the latter 
portion runs clear. It is put altogether into large hogsheads, generally holding 100 to 115 
gallons each in Herefordshire, but in Devonshire the hogshead invariably contains 50 gallons. The 
barrels are not quite filled up, a slight “ullage,” as the unfilled space at the top of the barrel is 
termed, being left. They are placed in a cool cellar or draughty outside building, to undergo the 
more active stage of fermentation. If the temperature is favourable, ranging from 6o° to 70°, very 
evident signs of increased action will soon appear. The bubbles of Carbonic Acid gas begin to rise 
quickly, and a constant hissing noise will be heard. These bubbles of gas carry up with them to 
the surface many of the lighter particles of the cellular tissues of the fruit that have passed through 
the press, and thus form a thick scum on the surface, to which cells of the yeast plants are gradually 
added in considerable quantity. This scum thus becomes a thick spongy crust, sometimes called the 
“ upper lees,” which is supported on the surface by the Carbonic Acid gas arising beneath it, so long 
as this gas is generated in sufficient quantity. At the same time that this action is going on the 
more solid particles of tissue sink through the fluid, accompanied v/ith a considerable portion of the 
mucilage, and an abundance of yeast cells. This deposit forms the “lees,” or “lower lees,” at the 
bottom of the barrel. 
As the fermentation declines the hissing moderates, since less Carbonic Acid Gas is generated ; 
the floating crust gets dry on the surface, cracks, and losing its buoyancy falls in fragments, to 
increase the amount of the lees below. By this time the liquor will have become moderately clear, or 
“ dropped bright,” as the phrase goes. It should then be racked off immediately and the temperature 
kept low. This is the crucial point of the whole process, and requires close observation and care ; for 
any delay at this stage incurs the risk of injurious secondary fermentation. The clear liquor should 
be racked, or run off from the lees into a fresh cask, perfectly clean and sweet, by means of a syphon, 
so as to prevent any unnecessary exposure to the air. A considerable “ ullage ” should be left in the 
barrel, and the bung is usually left open for some days, or even weeks. It is better, however, to close 
the cask with a bung through which a curved tube passes, one end open below the bung, and therefore 
in the “ullage” space of the cask; and the other end bent down and up again so as to hold 
a tablespoonful or two of water, placed in the outside bend ; or the outer end of the bent tube 
may itself be put in a shallow cup of water without being turned up again ; so that if any excess of 
gas should be formed in the barrel, its pressure would force it to escape through the tube and 
water, whilst the outer atmospheric air would be prevented from passing into the barrel by the water 
in the tube itself, or in the vessel it terminates in. This tube may be made of zinc, or other 
metal, but it is better and equally cheap to have it of glass, because the amount of pressure from 
the gas within the barrel can then be seen at a glance. 
If at the end of a week the liquor remains quiet, and becomes more clear, an ounce of 
dissolved isinglass should be added to each hogshead, and the vessels permanently closed. The 
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