when "racking" and add a pint to a quart
of a good grade cider vinegar. Let it stand in a warm place, well
covered with cheesecloth, and in from four to ten days a granular,
brownish cake should begin to form. This starter can then be put
directly into the casks, a pint or more to each cask. If the starter
develops a white, slimy coat, throw it out and start again. For all of
this second stage of fermentation follow the same plan as at first. Fill
the barrels not over two-thirds full, use a cotton plug or cheesecloth
screen at the bung and keep at a warm temperature. The essentials again
are air and warmth, with a good vinegar starter. Under these conditions
the vinegar may be ready in from two to ten months. If the usual plan of
"natural" fermentation is followed, and the cask is kept at a low
temperature, it may be three years before the vinegar is ready.

When the vinegar seems to be completed, send a sample to the State Dairy
and Food Commission at the Capitol for analysis. If they say it is
completed, "rack" off and strain again into clean barrels, this time
filling full and driving in the bung. This will prevent loss from
evaporation, and the vinegar can be sold at any time. The state law
requires that cider vinegars sold in the state measure up to a certain
standard--namely, four per cent. of acetic acid, 1.6 grams per 100 cc.
of solids, and .25 grams per 100 cc. of ash.

So much for vinegar making in general. For Minnesota conditions little
is known about the definite behavior of any apple varieties. This has
led to the study of vinegar making as a problem for the Experiment
Station. The Division of Horticulture is carrying on variety tests to
determine the yields of juice at different stages of maturity, the
efficiency of types of presses, labor costs per gallon, and the
production of vinegar from each variety to determine its value. The
Division of Agricultural Chemistry makes analyses of the sweet cider to
determine the composition and vinegar prospects, and also analyzes the
vinegars at various stages. The work has been carried on for two seasons
and is showing some interesting facts. These must, however, be checked
with further work before definite statements can be published.

As to machines, our results show that the press with press cloths will
outyield nearly two to one the press with the barrel or drum. However, a
strong grain sack used to catch the pomace and used to confine it in the
drum will give