406 
only heated up to 149° F. (65° C.) in 
the hot water and then removed would 
surely spoil. These cans remained sound, 
however, and thus the period of heating 
indicated as sufficient for canning is un- 
expectedly short. When the cans were 
removed, they were cooled over night and 
allowed to stand in the same room as 
that in which the bottles were held. Ow- 
ing to the large bulk of juice in the 
cans of the size employed (1 gallon), it 
is evident that the juice was maintained 
at a sterilizing temperature longer than if 
bottles or small-sized cans had been used. 
This fact must be kept in mind if the 
results here obtained are applied to other 
sizes than gallon cans. 
The Carbonation of the Juice 
In addition to experimental work on 
clarifying and on heating the juice, in- 
vestigations were made on carbonating it 
with a view to disguising the slight cook- 
ed taste which it is impossible entirely 
to avoid. Carbonating also increases the 
palatability of the juice in the opinion 
of many persons. The method used con- 
Sisted in carbonating the juice under 
slight pressure and then heating in bot- 
tles or cans, and no difficulty was en- 
countered. In the simple experiments de- 
vised and carried on in connection with 
this work, the carbon dioxid (carbonic- 
acid gas) was secured from a firm hand- 
ling soda-water supplies. It was obtained 
in liquid form in a steel cylinder furnish- 
ed with a reduction valve and a gauge 
and delivery tube, so as to deliver at pres- 
sures up to 30 pounds. After clarification, 
the juice was carbonated by pouring it 
into a clean keg and running in the gas 
up to a pressure of 15 pounds. 
The keg was provided with a thick 
pine bung, through the middle of which 
was bored a half-inch hole, which received 
the rubber delivery tube from the cy- 
linder of compressed gas. The bung was 
soaked in water for a few minutes be- 
fore 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. About 
ENCYCLOPEDIA OF PRACTICAL HORTICULTURE 
12 gallons of juice were poured into the 
keg. Carbon dioxid was admitted before 
driving the bung in airtight in order 
to expel the air which fills the space in 
the keg not occupied by the juice. The 
bung was then driven in by tapping with 
a hammer and more gas admitted. The 
keg was vigorously rocked so as to thor. 
oughly agitate the juice and so accelerate 
the absorption of the gas. 
The gauge was watched, and in these 
experiments the pressure was not allowed 
to go beyond 15 pounds per square inch. 
The juice used in the carbonating work 
was quite cool, ranging from 48° to ¢@8° 
F, (9° to 20° C.) in the different expert- 
ments. As the carbonating of liquids is 
apparently well understood, no attempts 
were made to correlate the pressure, tem- 
perature, and amount of gas which could 
be dissolved in the juice. In these ex- 
periments the juice was carbonated at a 
pressure not exceeding 15 pounds until a 
sample was drawn tasting distinctly of 
the gas, this being the amount of car. 
bonation desired. Working under these 
conditions in the different trials, from 
fifteen minutes to one-half hour was re- 
quired to carbonate 12 gallons of juice. 
The stream of gas was then stopped, the 
bung cautiously loosened, the contents 
of the keg poured out, and the juice bot- 
tled or canned. 
The gas remains for some time in the 
juice when under atmospheric pressure 
and only gradually diminishes in quan- 
tity, so that great haste in sealing the 
juice is not necessary. If the carbonated 
juice is to be sterilized in cans they 
must be heated in stout frames to pre- 
vent distortion of the can while hot and 
consequent bursting. The finished canned 
product bulges the ends of the cans to 
some extent, but not enough to cause 
permanent bending. The juice must not 
be too highly charged with the gas nor 
removed from the frames while still hot, 
or such bending, with consequent weak- 
ening of the soldered joints and bursting 
of the can, may occur. 
The Best Containers for Sterilizing Juice 
In the work with juice treated as above 
described, bottles and cans have been 
