Ice in the refrigerator is probably about 0°C., but ice from out of
doors on a cold winter day may have a temperature far below 0°C. When
ice at a very low temperature is used for freezing, a brine will form more
quickly and freezing start sooner if water is poured over the ice and salt.
Proportion of Ice and Salt for Freezing and Packing
Rate at which the temperature is lowered. The rate at which the
temperature of the brine and thus also that of the mix to be frozen is
lowered depends on the proportion of ice and salt, and on the fineness
of division of the ice and salt. Small pieces of ice provide greater surface
and thus melt faster than large pieces. Fine salt dissolves more quickly than
coarse salt, but a fine table salt is likely to lump. Crushed rock salt is good
to use.
Two procedures are used in freezing. The smooth, velvety texture
of ice cream and ices depends on several factors. One important factor is
88 FREEZING
the size of the crystals formed. The proportion of ingredients, their treat-
ment, and the incorporation of air bubbles into the mixture while it is
freezing are also important. Small crystals may be obtained by the quick-
freezing method. A very low temperature is used, the mass being frozen
so rapidly that many nuclei are formed and there is little crystal growth
because of the short time. This process is easier to use commercially than
in the home, because of the very low temperature employed for freezing.
Judging from reports in the ice-cream trade journals, it is successful in
some instances and not in others.
The other procedure is to freeze at a slower rate, depending on agita-
tion to form many nuclei. Air is incorporated in the mix in both processes.
A temperature of — 8° to — 10°C. is sufficiently low to freeze most ice
creams, sherbets, and ices. For home freezing, 1 part of salt to 8 of ice
is a good proportion. Commercially, 1 part of salt to 12 of ice is often
used. Washburn states that a proportion of 1 part of salt to 40 parts of ice
will freeze if given ample time. The air globules are retained in the mixture
better after it has nearly reached the freezing point. The air is beaten
in by the dasher paddles. In freezing very rapidly there is not time to
incorporate as much air as when the mix is frozen at a somewhat slower
rate.
Packing the freezer. Commercially most ice cream is now held in
mechanically operated freezing units or rooms, although the same propor-
tions of ice and salt may be used for packing that are used for freezing.
For home-made ice cream the same proportion of ice and salt may be used
as for home freezing, or about 1 of salt to 8 of ice. In packing, the ice
should be pressed down tight in the can. This will force the surplus water
out of the opening in the container. If the water is drained off it only takes
a longer time for the brine to form again, and cooling is slower. A little salt
should be added to the ice left in the freezer before the new ice is added.
For home-made ice cream that is hot to stand very long before serving, a
larger quantity of salt may be used to advantage. This will cause the
temperature to drop quickly and hardening of the cream will take place
more rapidly.
Page 70
Presented as published in 1932. Historical recipes may not meet modern food-safety standards. Cook from the modern interpretation, not the original instructions.
AI-modernized reading of the original text
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Ice in the refrigerator is probably about 0°C., but ice from out of
doors on a cold winter day may have a temperature far below 0°C. When
ice at a very low temperature is used for freezing, a brine will form more
quickly and freezing start sooner if water is poured over the ice and salt.
Proportion of Ice and Salt for Freezing and Packing
Rate at which the temperature is lowered. The rate at which the
temperature of the brine and thus also that of the mix to be frozen is
lowered depends on the proportion of ice and salt, and on the fineness
of division of the ice and salt. Small pieces of ice provide greater surface
and thus melt faster than large pieces. Fine salt dissolves more quickly than
coarse salt, but a fine table salt is likely to lump. Crushed rock salt is good
to use.
Two procedures are used in freezing. The smooth, velvety texture
of ice cream and ices depends on several factors. One important factor is
88 FREEZING
the size of the crystals formed. The proportion of ingredients, their treat-
ment, and the incorporation of air bubbles into the mixture while it is
freezing are also important. Small crystals may be obtained by the quick-
freezing method. A very low temperature is used, the mass being frozen
so rapidly that many nuclei are formed and there is little crystal growth
because of the short time. This process is easier to use commercially than
in the home, because of the very low temperature employed for freezing.
Judging from reports in the ice-cream trade journals, it is successful in
some instances and not in others.
The other procedure is to freeze at a slower rate, depending on agita-
tion to form many nuclei. Air is incorporated in the mix in both processes.
A temperature of — 8° to — 10°C. is sufficiently low to freeze most ice
creams, sherbets, and ices. For home freezing, 1 part of salt to 8 of ice
is a good proportion. Commercially, 1 part of salt to 12 of ice is often
used. Washburn states that a proportion of 1 part of salt to 40 parts of ice
will freeze if given ample time. The air globules are retained in the mixture
better after it has nearly reached the freezing point. The air is beaten
in by the dasher paddles. In freezing very rapidly there is not time to
incorporate as much air as when the mix is frozen at a somewhat slower
rate.
Packing the freezer. Commercially most ice cream is now held in
mechanically operated freezing units or rooms, although the same propor-
tions of ice and salt may be used for packing that are used for freezing.
For home-made ice cream the same proportion of ice and salt may be used
as for home freezing, or about 1 of salt to 8 of ice. In packing, the ice
should be pressed down tight in the can. This will force the surplus water
out of the opening in the container. If the water is drained off it only takes
a longer time for the brine to form again, and cooling is slower. A little salt
should be added to the ice left in the freezer before the new ice is added.
For home-made ice cream that is hot to stand very long before serving, a
larger quantity of salt may be used to advantage. This will cause the
temperature to drop quickly and hardening of the cream will take place
more rapidly.