VINEGAR-MAKING. 221 
process is also dependent upon the presence and active growth of the 
vinegar plants. 
Use of Pure Cultures in Vinegar-making. The different 
types of vinegar-making organisms vary much, requiring quite 
different conditions of temperature for their best work. In the 
processes of manufacture hitherto used considerable losses have 
resulted from the fact that the acetic acid formed is destroyed by 
the further action of the bacteria. The fermentation is apt to be 
irregular and, even under the same conditions, does not always 
produce equally desirable results. The reasons for the irregularities 
are to be found in the fact that, in different factories, sometimes 
even in the same factory at different times, many varieties of the 
vinegar organisms are found. Moreover, several of these organisms 
are almost sure to be found together in any mass of natural " mother." 
It is impossible to devise conditions that will be most favorable for 
all of the organisms, and hence, with a "mother" composed of 
many varieties, there is sure to be some loss. Theoretically, it 
would seem that vinegar-making could be improved by the use 
of pure cultures of these organisms. With a pure culture it would 
be possible to make the conditions such as to produce the best 
results with the variety in question, and thus prevent the losses 
that come from one variety destroying the product of another 
variety. The use of pure cultures has revolutionized brewing, 
has greatly improved the methods of butter-making, and is rapidly 
changing the process of cheese-making. Bacteriologists feel 
confident that the same principal can be applied to vinegar-making. 
Hitherto there has been but little application of pure cultures 
to vinegar-making. To obtain absolutely pure cultures is difficult, 
and to keep them pure from subsequent contamination is more 
difficult still. Vinegar-makers have not thought the advantages 
derived from such methods sufficient to pay for the labor and trouble 
of applying them. They have, to a considerable extent, adopted 
rougher methods of obtaining the vinegar organism in quantity 
and in a comparatively pure condition. A little white spirit vinegar 
is filtered through fine bolting cloth to remove the vinegar eels. 
This is mixed with a little alcohol of 90 per cent, volume, and some 
