449 
The surest way of restoring fermentation in a “stuck” vat, or 
of preventing the temperature rising too high, is, however, to use 
a refrigerator or wine-cooler, 
Full-bodied wine of high gravity may remain sweetish owing to 
exhaustion of yeast-food, which consists of oxygen, nitrogen, phos- 
phorie acid, and potash. Of these, potash is present in ample quan- 
tities in the shape of cream of tartar. Phosphoric acid appears to 
be seldom deficient. Oxygen is easily supplied by aeration. Nitro- 
gen in a form acceptable to the yeast plant is not always abundant 
enough. “Ammonia” is the form most readily absorbed by yeast, 
while “nitrates” appear to be useless. A yeast stimulant in the 
shape of ammonia salts may be usef'ul at the close of a sluggish 
fermentation of such high gravity, full-bodied wines, the dose not 
to exceed loz. per 100 gallons of ammonium phosphate. If used in 
excess, it acts as food for bacteria as well as for yeast. Of am- 
monium phosphate there are two forms, viz., the mono-ammonia or 
acid phosphate, and the bi-ammonia or crystallised form. The first 
is preferable. 
“Sweetish wine” from “stuck” vats is very dangerous to hold, 
as secondary fermentation sets in when the summer comes round. 
If not fortified at once, and it is desired to make it ferment out, 
good, healthy “levure” or yeast should be added, and in addition a 
little phosphate of ammonia, if procurable, of the dose indicated. 
REFRIGERATORS, also called ‘“‘attemperators,” are mechanical 
devices for the purpose of cooling liquids, whether it be milk, as in 
a dairy, mash in a brewery, or must in a winery. 
Several types are in use for that purpose, those which have 
met with greater favour being :— 
Metal spiral coils, plunged in the fermenting must, and through 
which cold water is passed, have hitherto been much used in brewer- 
ies as well as wineries. In consists of a horizontal cireular coil to suit 
the shape of the vat, and made of tinned copper pipes one-sixteentu 
of an inch thick and one inch to one and a-quarter inch outside 
diameter, with supporting stays and suspending rods, by which it 
may be hung in the vat at any desired depth. The pipes are fitted 
with unions for connecting india-rubber hose for the supply of 
cooling water. When required to be removed, after fermentation, 
for cleaning purposes, it is readily hoisted by pulley blocks out of 
the vat. The pipes are set at a distance of about four inches apart, 
so as to allow of rapid and thorough cleaning. 
Amongst other advantages, this attemperator is easy to con- 
struct, fairly cheap, and can be fitted up anywhere, being simply 
hung on a beam over the top of any vat. It is, by means of the 
pulley blocks and a counterpoise hitched on at the other end of the 
chain, set at any depth in the fermenting wine. A good depth, I 
