The Indiana State sentinel. [volume] (Indianapolis) 1868-1895, 1880-12-29
Properties of Good Vinegar.

Properties of Good Vinegar.
H Kratzer says the quality of good vine
/ gar may be detected by its taste by its color
and by its smell; for instance, good vinegar
must have sour taste, which is not altered
by free alcohol or other foreign substances
As to the color, it may be that of the water
clear or of the wine-yellow vinegar it must
always be perfectly pellucid, and when
| rubbed between the fingers the odor must
be acid without having any similarity to
spoiled liquors; but before all, vinegar il
| brought to the lips. must not produce either
a feeling of bluntness, Tor if this should re
the case we can be sure that the vinegar is
adulterated.
Authorizations are sometimes produced by
/ the addition of mineral acids sometimes
| by vegetable matters. OF the former es-
| pecially sulphuric acid, muriatlc acid. and
| sometimes even nitric acid, are used; of the
latter we mention cayenne pepper, bertram
root, common pepper etc. The method of
detecting these authorizations is the follow
| ing:
| If sulphuric acid is suspected of being
present we should pour some of the vinegar
| into small test tube, and add some chlorate
of acetate of barium; if by the additional of
/ this n white color is produced or after a time
J white precipitate is formed, then the vinegar
has been adulterated with sulphuric acid.
| If the vinegar only becomes slightly turbid,
| the reason may be accounted for by
| the fact that the water which was
used for the fabrication of the vine
gar contained sulphate of lime. To be
certain that the vinegar contains free sui
| phuric, the following method should be
employed A small portion of vinegar is
put into an evaporation dish and there evap-
| Grated until ii is condensed TO about one
tenth its weight; the remainder is dissolved
in alcohol, filtered, and diluted with water,
and finally a solution of chlorate of barlum
| is added. III now the vinegar shOwsa turbid
white color the adulteration by sulphuric
acid may be assumed with certainty. Re
Gently, for the detection of mineral acids, a
new reagent has been devised, which can be
/ well recommended, viz, methyl-aniline-
violent. A diluted solution of this sub
stance does not change color at all with pure
vinegar, while if the slightest quantity of
mineral acids is present it takes a blue
green color
If an adulteration of muriatic acid sus-
pected some drops of solution of nitrate
of silver should be added to the vinegar;
/ if white haky precipitation is formed,
which is blackened by the sunlight, and
can not be dissolved after an excess of nitric
acid has been added, then the adulIeration
is proved.
To prove the presence of nitric acid
small quantity of potassium should be
mixed with the vinegar, and after the liquid
has been evaporated the remainder should
! be placed upon some glowing charcoal. If
decrepitation takes place the adulteration
may be taken for granted, otherwise the salt
burns without noise and difiuses an odor
similar to that of burnt sugar
To detect the adulteration by sharp vege-
table matters the following method may be
employed:
A small quantity of the vinegar, having
the weight of $50 grains, is slowly eyaporated
until some brown liquid remains. If it was
adulterated, this liquid has sharp singing
taste while if this is not the case, it will
have only an acid taste
| A still more simple method is to moisten
the upper lip with vinegar, the purity OF
which is acknowledged, while the under lip
is moistened with the vinegar which is TO be
examined, and both are to be permitted to
dry If the vinegar has been adulterated in
the manner mentioned, disagreeable itch
! ing or singing is felt on the under lip, while
| the upper lip is not affected.
A third method for the same purpose is to
neutralize the vinegar by carbonate of soda;
| the acid taste of the vinegar is thus removed
and the sharp taste of spices remains.
If vinegar is kept in copper vessels it is
often dangerous to the health. In order to
discover whether this has been the ease, sui
phurated hydrogen is employed; if the vim
| egar first turns a brown color, and If finally
a black precipitate is formed, the presence
OF copper is evident. Vinegar which has
been Kept in tin vessels gives yellow pre-
cipitate when mixed with sulphurated n.y.
drogen; such as has been kept in zinc yes
sells gives a white precipitate, and the pres
ence of lead is indicated by white precip
itate
If iron vessels have been used for the
preservation of vinegar, the latter loses its
value for many industrial purposes The
presence of iron can be detected by the adj
dition of ferrocyanide of potassium, which
in this case produces a blue precipitate
4 The strength of the vinegar is found in
the usual way by means of an acetometer.
That OF Otto deserves to be recommended.