An acid fruit is the most suitable for jelly making, though in some of
the acid fruits, the strawberry, for example, the quantity of the
jelly-making pectin is so small that it is difficult to make jelly with
this fruit. If, however, some currant juice be added to the strawberry
juice a pleasant jelly will be the result; yet, of course, the flavor of
the strawberry will be modified. Here is a list of the most desirable
fruits for jelly making. The very best are given first: Currant, crab
apple, apple, quince, grape, blackberry, raspberry, peach.
Apples make a very mild jelly, and it may be flavored with fruits,
flowers, or spices. If the apples are acid it is not advisable to use
any flavor.
Juicy fruits, such as currants, raspberries, etc., should not be
gathered after a rain, for they will have absorbed so much water as to
make it difficult, without excessive boiling, to get the juice to jelly.
If berries are sandy or dusty it will be necessary to wash them, but the
work should be done very quickly so that the fruit may not absorb much
water. (See washing fruit, p. 13.)
Large fruits, such as apples, peaches, and pears, must be boiled in
water until soft. The strained liquid will contain the flavoring matter
and pectin.
It requires more work and skill to make jellies from the fruits to which
water must be added than from the juicy fruits. If the juicy fruits are
gathered at the proper time one may be nearly sure that they contain the
right proportion of water. If gathered after a rain the fruit must be
boiled a little longer that the superfluous water may pass off in steam.
In the case of the large fruits a fair estimate is 3 quarts of strained
juice from 8 quarts of fruit and about 4 quarts of water. If the
quantity of juice is greater than this it should be boiled down to 3
quarts.
Apples will always require 4 quarts of water to 8 quarts of fruit, but
juicy peaches and plums will require only 3 or 3½ quarts.
The jelly will be clearer and finer if the fruit is simmered gently and
not stirred during the cooking.
It is always best to strain the juice first through cheese cloth and
without pressure. If the cloth is double the juice will be quite clear.
When a very clear jelly is desired the strained juice should pass
through a flannel or felt bag. The juice may be pressed from the fruit
left in the strainer and used in marmalade or for a second-quality
jelly.
To make jelly that will not crystallize (candy) the right proportion of
sugar must be added to the fruit juice. If the fruit contains a high
percentage of sugar, the quantity of added sugar should be a little less
than the quantity of fruit juice. That is to say, in a season when there
has been a great deal of heat and sunshine there will be more sugar in
the fruit than in a cold, wet season; consequently, 1 pint of currant
juice will require but three-quarters of a pint of sugar. But in a cold,
wet season the pint of sugar for the pint of juice must be measured
generously.
Another cause of the jelly crystallizing is hard boiling. When the sirup
boils so rapidly that particles of it are thrown on the upper part of
the sides of the preserving kettle they often form crystals. If these
crystals are stirred into the sirup they are apt to cause the mass to
crystallize in time.
The use of the sirup gauge and care not to boil the sirup too violently
would do away with all uncertainty in jelly making. The sirup gauge
should register 25°, no matter what kind of fruit is used. (See p. 15.)
Jellies should be covered closely and kept in a cool, dry, dark place.