The news and herald. (Winnsboro, S.C.) 1877-1900, 1881-07-12
Testing NIalts for Acidity.

The existence Of abnormal acidity IN
malt is not only injurious in itself, but
this very excess of acidity undoubtedly
hastens changes in the resulting wort
and beer, which tend to their ultimate
destruction rs drinkable fluids. From
the commencement of the mailing sen
son till the warmer weather of spring
sets i'll, the development of acidity in.
malts proceeds but slowly, but after
April, and especially in malts which have
been stored for some time, the amount
OF acidity will be found to have increased
10 determine with accuracy the absolute
quantity Of acid in sample Of malt is M
operation attended with some difficulty.
and requires the skill and appliances of
practical chemist but valuable com
parative test for acidity can be made by
any brewer with but few appliances, and
with sbut little knowledge of chemical
manipulation. We say comparative test
III cOntradistinction to an absolute test,
because the former will really give the
brewer all tho information he requires
he wants to, compare one malt with
another, and he is generally able to fix
his own standard of excellence. There
fore i'll testing malts for acidity land the
remark applies equally to othcryaualities)
all that is necessary for the brewer to do
is to submit them all to precisely the
same treatment. Two inftlsions of the
malt arc prepared, one with cold water
and the other ut the average mashing
temperature, say 1G0 deg. Fab, all
samples to be tested must be treated in
exactly the same manner MS regards quail
ties, time, and temperature, and they
are then passed through n filter paper,
and the ncidity determined in each by
means of standard alkaline solution,
using delicate litmus papers as the indi-
GATOR. 1t is not well to operate upon too
small quantity, and in practice 1000
grammcs to q liter of water will be found
convenient. Every sample of malt must
he crushed to the same state of tinencss,
and for this purpose IN ordinary coffee
mill answers admirably. The water used
i'll making the infusions should be pure
distilled water, unless water of very
constant composition, such rs is supplied
to London. is ut hand.
The standard alkaline solution is best
made with ammonia, and can be Of any
desired strength, but of course very di-
lutte; it may be titrated so that every
cubic centimeter corresponds to O-01 per
cent. of Tactic acid, but any other strength
will do equally well, as the tests we sug-
gest are only for the purpose of compnr-
ing samples of malt ono with another.
The dcidity of the cold infusion gives the
actual amount of acid existing in the
malt, but that of the hot infusion gives,
i'll addition, the amount of acid developed
during the mashing process. From tho
experience derived in the examination of
many hundred samples of malt, we arc
able to assert that the presence of nh ex-
ccssivc amount of acidity in the hot in
fusion is an almost srlre sign of unsound-
ness in the malt. The difference in the
acidities of the cold and hot infusions
onght never to exceed one-fo,rth of the
acidity of the cold infusion; thus, sup
posing malt gives a cold infusion re-
quiring 20 cubic centimetcrs of the
standard solution to exactly ncutralize
it, the hot infusion ought not to require
more than 25 C. c. This method of com.
parativc testing may also be extended to
the color and gravity OF the resulting
worts, and much useful information as
to the quality of the malt can thus be
obtained.