EXPERIMENT STATION BULLETINS. 5l7 



percentage of certain chemical elements necessary for the nutriment of 

 the yeasts, consequently these have to be supplied in some form. The 

 most important of these are nitrogen and phosphorus, which may be 

 supplied as a food for the yeast in the form of ammonium salts and 

 phosphates respectively. A formula which has been found to give good 

 results experimentally is given below. It is sufficient for a barrel of 

 vinegar. 



Formula : 



Strained or extracted honey 40 to 45 lbs. 



Water 30 gal. 



Potassium tartrate 2 oz. 



Ammonium phosphate 2 oz. 



The diluted honey should register 15 per cent sugar by the sacchari- 

 meter. As heat must be used to dilute the honey it will be necessary to 

 inoculate this solution with a pure culture of the wine yeast and later 

 with the vinegar bacteria as the heat employed will destroy practically 

 all of the organisms already present. 



Another formula from the Arizona Agricultural Experiment Station 

 is as follows : 



Strained honey 40 to 45 lbs. 



Water 30 gal. 



Ammonium chloride 4 oz. 



Potassium bicarbonate 2 oz. 



Sodium phosphate 2 oz. 



Either formula will furnish sufficient food for the yeasts at a cost of 

 about twenty-five cents per barrel. Of course, the larger the quantities 

 made, the less will be the proportionate cost of the chemicals per barrel. 

 These chemicals are absolutely harmless and cannot in any way be con- 

 sidered as adulterants. 



Honey vinegar of most excellent flavor containing over 8 per cent 

 acetic acid is being made continually from waste honey by the entomolo- 

 gist of this experiment station, using a similar formula. On page 505 

 the different kinds of unmarketable honey are given which may be util- 

 ized in this way. 



Maple syrup vinegar: Dilute or boil down maple syrup until 15 per 

 cent sugar is present (or until it weighs 9 lbs. to the gallon.) 

 Then use the following formula: 



Diluted maple syrup 30 gal. 



Ammonium sulfate 2 oz. 



Sodium phosphate 2 oz. 



and inoculate as with the honey vinegar. Skimmings from maple syrup, 

 or maple syrup which is scorched or otherwise unmarketable can be 

 utilized in this way to advantage. 



Glucose vinegar is made from the acetification of alcohol obtained from 

 the fermentation of commercial glucose. This vinegar usually possesses 

 the odor and taste of fermented starch. 



