CARBONATIXG. 17 



Seventh. The best conditions, as worked out by experiment, for clarifying apple 

 juice are as follows, working with a hand machine with a capacity for milk of 450 

 pounds per hour. 



(a) The juice must be freshly expressed and. to be of high quality, should be pre- 

 pared from sound, well-ripened fall or winter apples of suitable varieties. 



(6) It should be received in a clean barrel or cask, which must not contain any fer- 

 mentation residues. This point is very important, as experience has shown that the 

 very fine deposit formed in fermenting juice can not be successfully removed by the 

 separator, and this deposit is difficult to clean from the sides and bottoms of fermen- 

 tation casks. a 



(c) In passing the juice through the separator, the necessary precautions as to oiling 

 and starting the machine must be used, and the crank should be run at the rate of 

 45 turns per minute. Twenty-five to forty gallons of fresh juice can be run through 

 before the capacity of the bowl for sediment is reached. The juice which comes 

 through the milk screw should be collected separately. 



(d) As soon as the milk screw becomes clogged the machine should be stopped and 

 the bowl cleaned. 



(e) The juice collected from the milk screw should be passed through again and 

 that coming from the milk screw collected as before. . 



The clarification of 25 gallons of juice (using one machine of the capacity indicated 

 and a juice containing sediment in such quantity that the run would fill the space 

 between the disks and the sides of the bowl with sediment) requires about one hour 

 and a quarter, the juice passing through the bowl twice. 



These details are given in order to assist others who may wish to 

 clarify in this way. Clarification by means of centrifugal force 

 could probably be greatly improved if a machine designed primarily 

 for the purpose were used. 



CARBONATING. 



Experiments in carbonating apple juice were carried on during 

 1906 to determine whether or not the palatability of the sterilized 

 juice could be increased and the slight cooked taste be disguised. 



METHODS EMPLOYED. 



The following methods were tried in the work of 1906: 



The juice was carbonated under slight pressure and then heated in bottles or cans. 

 In the simple experiments conducted in connection with this work, the carbon dioxid 

 (carbonic-acid gas) was secured from a firm dealing in soda-water supplies. It was 

 obtained in liquid form in a steel cylinder furnished with a reduction valve and a 

 gauge and delivery tube, so as to deliver at a pressure up to 30 pounds. 



After clarifying, the juice was carbonated by pouring about 12 gallons of it into a 

 clean keg and running in the gas up to a pressure of 15 pounds. The keg was pro- 

 vided with a thick pine bung, through the middle of which was bored a half-inch hole, 

 which received the rubber delivery tube from the cylinder of compressed gas. The 

 bung was soaked in water for a few minutes before use, so that it could be driven in to 

 make a tight joint, and was so fitted that it projected beyond the surface of the keg and 

 could be readily loosened when carbonation was finished. Carbon dioxid was ad- 



This point is confirmed in the experiments of 1907 (see p. 15). 



