Home-Made Cider Vinegar 
ii 
sweet cider into an old vinegar barrel? Here is the reason: We 
have seen from what has gone before that alcohol is produced from 
the fermentation of the sugar. We shall soon learn that the acetic 
acid of the vinegar is formed from this alcohol. Now, in order 
to obtain the maximum amount of acetic acid, it is necessary to 
have as much alcohol as possible in the hard cider, and this can 
be obtained only by the complete conversion of all the sugar into 
alcohol and carbon dioxide gas. 'The complete destruction of the 
sugar can be accomplished only by the uninterrupted action of the 
yeast,, and the presence of “mother” of vinegar by producing acetic 
acid interferes seriously with this fermentation. The yeast cells 
are either killed or their useful activity is checked long before all 
of the sugar has been changed into alcohol. This is the condition 
of a very large percentage of farm vinegar—just hard cider that 
will not and never will make vinegar. It means just this: 
-A small part of the sugar was made into alcohol and this 
alcohol was at once changed to acetic acid by the “mother” pres¬ 
ent; this acetic acid killed the yeast so that no more sugar could 
be changed to alcohol and no more alcohol being found, no more 
acetic acid could be made by the “mother.” We have a weak, 
worthless something neither vinegar nor hard cider with consid¬ 
erable unfermented sugar still present and incapable of further fer¬ 
mentation because no yeast can develop in the weak acetic acid 
solution. 
The Acetic Acid Fermentation. 
The second step in vinegar making is the change of the alco¬ 
hol. of the hard cider into the acetic acid of the finished product. 
This is accomplished by the acetic acid germ, another microscopic 
plant still smaller than the yeast. In some peculiar way it is able 
to bring about a union between the alcohol of the hard cider and 
the oxygen of the air so that the alcohol is transformed into acetic 
acid and water. 
As soon as the alcoholic fermentation, described in the pre¬ 
ceding section, is completed, draw off the clear liquid, being very 
careful not to disturb the sediment in the barrel. Wash out the 
barrel thoroughly and replace the hard cider. It is believed that 
removing this sediment permits the acetic acid to form somewhat 
more quickly, and furthermore, the sediment may undergo decom¬ 
position and impart a disagreeable flavor to the cider. Again, 
these dregs may harbor livine bacteria which either destroy acetic 
acid or interfere with its formation. 
This done, we are now ready to introduce the acetic acid 
