EXPERIMENT STATION BULLETINS. 515 



the common farm vinegar of Michigan and its problems are dealt with 

 fully in this bulletin. For profit apples should be expressed with a 

 power press. With a hand press only 2 gallons of juice could be secured 

 at the Virginia Station, while with a power press 4 gallons were obtained. 



Grape or loine vinegar: Michigan has many vineyards; many of the 

 grapes grown are unsuitable for marketing and can be converted into 

 excellent vinegar. Such vinegar can be sold at a profit and at a price 

 which formerly compared well with that of grape wine. On the open 

 market grape vinegar can compete with other kinds when quality is con- 

 sidered. 



Good grape vinegar cannot be made from moldy or decayed grapes. 

 Its manufacture requires the same knowledge and care as with apple 

 vinegar, and it can be successfully produced on a small scale for domestic 

 purposes. 



The quantity of vinegar obtained from various kinds of grapes differs 

 due to the fact that the quantities of stems, seeds, skins, and fermentable 

 sugars vary with each kind of grape. It has been found at the California 

 Agricultural Experiment Station that one ton of grapes of 20 degrees 

 Balling (20 per cent, sugar on Balling's saccharimeter) should yield 

 on the average 135 gallons of vinegar of 9.8 per cent, acetic acid. 



White wine vinegar, a light yellow vinegar, is generally recognized 

 as the most superior of all vinegars as to flavor and bouquet. This vinegar 

 is made from white wine, which is the result of the alcoholic fermenta- 

 tion of either the pulp alone of purple or red grapes, or of the whole 

 fruit in the case of the Avhite grape. The color of wine vinegar made 

 from red wine is also red, due to the fermentation of the whole grape. 



Of course, a fine quality of grape vinegar cannot compete in cheap- 

 ness with that "made from distilled alcohol (the common incorrectly 

 called "white wine vinegar" of commerce) or the numerous waste prod- 

 ucts which at present are the source of the main bulk of the vinegar 

 found in commerce," but it most certainly excels it in flavor and bouquet. 

 If grape vinegar "is to be produced at a profit, it must be made intelli- 

 gently, and in such a manner as to produce and preserve those qualities 

 to which it owes its reputation for superiority over all other classes of 

 vinegar." 



Peach vinegar: In seasons of heavy crops there are available large 

 quantities of sound, overripe peaches which it will not pay to market 

 as fresh fruit. Particularly is this the case when hot weather causes 

 the fruit to ripen rapidly. The best peach vinegar will be made of fruit 

 of this type. Kotten peaches, especially if the rotten spots are left on, 

 make a poor vinegar, generally low in acid, with disagreeable flavors 

 and after-tastes, which darkens rapidly on exposure to the air. 



Peaches contain sufficient fermentable sugar for vinegar-making but 

 they are on the average about 1 per cent, lower in their total sugar 

 content than average apple juices. This, of course, results first in a 

 lower percentage of alcohol, then of acetic acid than with ordinary 

 cider. Average percentages of acetic acid in peach and apple vinegars 

 are respectively 4.G2 and 7.45 as determined by the U. S. Government. 

 A large percentage of the sugars go to waste if peaches are allowed to 

 rot before being made into vinegar, the sugar being used by the molds 

 causing the rot. 



