Putting Food By - Janet Greene [132]
Squeezing the jelly bag forces through bits of pulp that will cloud the jelly, but pressing the back of a wooden spoon against the bag will often quicken the flow without clouding the juice.
If there is traffic through the room, with attendant insects and dust, drape a clean sheet over the whole business.
Be fussy about washing the jelly bag after each use and rinsing it well; even a little diluted juice left in the fabric will spoil, and a musty, winey bag will hurt the next juice that’s strained in it.
Refrigerate, in a tightly covered sterilized container, any juice left over from measuring for the batch of jelly.
Sugar and Pectin
When you add the sugar depends on the type of commercial pectin you use. Each recipe stipulates the type—and they are not interchangeable . Always follow the recipe exactly, because time and quantity variations almost always bring failure.
Powdered pectin is added to the strained juice before heating. Heat rapidly, bringing to a full rolling boil—i.e., a boil which cannot be stirred down; then add the sugar, bring again to a full rolling boil, and boil for 1 minute.
Liquid pectin (except for homemade pectin, above) is added to the strained juice and sugar after the mixture is brought to a full boil. Stir constantly during heating. Add pectin, bring again to a full rolling boil, boil for 1 minute.
WITHOUT ADDED COMMERCIAL PECTIN
Jellies with enough natural pectin (like Basic Apple Jelly) require less sugar per cup of juice than jellies with added store-bought pectin do. The longer cooking needed to reach the jelly stage produces the right proportion of sweetness, acid, and pectin.
Testing for Doneness
Because barometric pressure as well as altitude affects the boiling point, make necessary adjustments for heights more than 1000 feet/305 meters above sea level, and for whether the day is close and damp, or clear and dry.
Jelly with added pectin will be done if boiled as the individual instructions for time and quantity specify.
Jelly without added pectin is done when it reaches 8 F (the Celsius comparison is meaningless here) above the boiling point of water—usually, under good conditions at 1000 feet/305 meters or less, this is 220 F/104.4 C. Be careful, however, never to heat any preserve made without added pectin past 225 F/107 C. If you do, it will have a ropey, gluey texture and a caramelized off-flavor.
If you have no jelly thermometer, use the Sheet Test. Dip a cold metal spoon in the boiling jelly and, holding it 12 to 18 inches above the kettle and out of the steam, turn it so the liquid runs off the side. If a couple of drops form and run together and then tear off the edge of the spoon in a sheet, the jelly is done.
BUT this test is not for jam: sheeting in the same manner means that the jam has cooked too long, and will be stiffer than the soft texture one is accustomed to.
Or use the Refrigerator (or Freezer) Test. Remove the kettle from the heat (so it won’t raise Cain while your back is turned) and spoon some hot, hot jelly onto a chilled saucer, and return the saucer to chilling for a minute. Then look at the jelly: if it wrinkles when you push it from the side, and seems generally tender-firm, it is ready to pour and seal.
Jelly at High Altitude
The Sheet Test is likely to be especially helpful if you live at 3500 ft/1067 m or more, because, since jelly boils at a lower temperature than it would in the sea-level zone, the result of the boiling is the important thing—not what the temperature was that brought it to the point of sheeting.
Progress of sheeting test, left to right.
(Drawing by Irving Perkins Associates)
Thus, with the gelling point set at 8 F/4.4 C above the boiling point of water at sea level, and you live in Duluth or Thunder Bay, you’d have jelly