14 
The Colorado Experiment Station 
implied, goes with the cultures, since it is not the purpose of the 
Experiment Station to exploit these products, but rather to dis¬ 
tribute them at the cost of production for experimental purposes. 
Inasmuch as one of the cultures is to be added to the sweet cider, 
the set should be obtained a few days, not longer, before the cider 
is to be made. 
Requests for cultures should be addressed to the Bacterio¬ 
logical Laboratory, Colorado Experiment Station, Fort Collins, 
Colorado, and should be accompanied by a remittance of fifty 
cents (50c). 
Directions For Using Pure Cultures in Making Vinegar 
Preparation of Yeast Culture. 
1. For each barrel of sweet cider, sterilize one two-quart Mason 
jar by washing thoroughly and boiling for five minutes in 
clean water. 
2. Cover the top of the jar with a single layer of clean muslin or 
cheese cloth just removed from boiling water and secure it 
in place by a string tied about the neck of the can. 
3. Select 6 or 8 medium sized ripe apples; pare and quarter or 
slice them; add one quart of water and boil till soft; strain 
liquid through clean cloth while hot into Mason jar, first 
removing the cloth covering from the top. 
4. Make up the volume of liquid to approximately one quart with 
boiling water; add 4 tablespoonfuls of sugar and replace 
the cloth immediately. 
5. When the liquid has cooled thoroughly, partly remove the cloth 
covering and add the contents of the culture bottle marked 
“Yeast.” Replace the cloth. Just previous to opening the 
culture bottle, shake thoroughly and immerse the lip and 
cork only, ten second in boiling water. Do not touch the 
lip while removing cork. 
6. Keep the jar in subdued light at a temperature of 75 degrees 
F. to 90 degrees F. After two to four days the foaming 
characteristic of alcoholic fermentation should appear. 
7. After four to six days, add the entire contents of the yeast jar 
to the barrel of freshly made sweet cider. The barrel must 
not he more than two-thirds full; it should be placed on its 
side, and the bung-hole be left open, or, better, plugged 
loosely with a tuft of clean cotton batting. 
8. Keep the barrel at 75 degrees F. to 85 degrees F. 
