Add a little chalk to the _must_, when it is somewhat sour; for the
acidity arising from citric and tartaric acids, there is thus formed
a precipitate of citrate and tartrate of lime, while the _must_
becomes sweeter, and yields a much finer wine. Too much chalk may
render the wine insipid, since it is proper to leave a little excess
of acid in the _must_. Concentrate the _must_ by boiling, and add the
proper quantity of chalk to the liquor, while it is still hot. Even
acid wine may be benefited by the addition of chalk. Oyster-shells
may be used with this view; and when calcined are a cleaner carbonate
of lime than common chalk.
_To Renovate Sick Wine._
Wines on the fret should be racked; if their own lees indicates decay
they should be racked on the sound lees of another wine of similar,
but stronger quality, to protract their decline; if this be done at
an early period, it may renovate the sick wine; on these occasions,
giving the sick wine a cooler place, will retard its progress to
acidity; if convenient, such wines should be forced and bottled.
Previous to bottling, or rather at the forcing, give it one, two, or
three table-spoonsful of calcined gypsum finely pulverised. This will
check its tendency to acidity, without exciting much intumescence,
without injuring the colour of the red wine, and without retarding
its coating to the bottle, which it rather promotes. The proper
forcing for red wines are, the whites of ten or twelve eggs, beat up
with one or two tea-spoonsful of salt per hogshead, and well worked
into the wine with a forcing-rod; the gypsum should be first boiled
in a little water. This is intended to check the acetous process. To
retard the vinous, the French are in the habit of burning sulphur
immediately under the cask, and possibly the sulphuric acid evolved
by the combustion, may check its progress and prevent the necessity
of an _admixture_.
_To Mellow Wine._
Cover the orifices of the vessels containing it with bladders closely
fastened instead of the usual materials, and an aqueous exhalation
will pass through the bladder, leaving some fine crystallizations on
the surface of the wine, which, when skimmed off, leaves the wine
in a highly improved state of flavour. Remnants of wine covered in
this manner, whether in bottles or casks, will not turn mouldy, as
when stopped in the usual way, but will be improved instead of being
deteriorated.
_German method of restoring sour Wines._
Put a small quantity of powdered charcoal in the wine: shake it, and
after it has remained still for forty-eight hours, decant steadily.
_To Concentrate Wines by Cold._
If any kind of wine be exposed to a sufficient degree of cold in
frosty weather, or be put into any place where ice continues all the
year, as in ice-houses, and there suffered to freeze, the superfluous
water contained in the wine will be frozen into ice, and will leave
the proper and truly essential part of the wine unfrozen, unless
the degree of cold should be very intense, or the wine but weak and
poor. When the frost is moderate, the experiment has no difficulty,
because not above a third or fourth part of the superfluous water
will be frozen in a whole night; but if the cold be very intense, the
best way is, at the end of a few hours, when a tolerable quantity of
ice is formed, to pour out the remaining fluid liquor, and set it in
another vessel to freeze again by itself.
The frozen part, or ice, consists only of the watery part of the
wine, and may be thrown away, and the liquid part retains all the
strength, and is to be preserved. This will never grow sour, musty,
or mouldy, and may at any time be reduced to wine of the common
strength, by adding to it as much water as will make it up to the
former quantity.