The Importance of Using Pectin, Glycerine and Marbles in Making Jam
There are several aids to quick setting of jams and jellies – bottled pectin and pectin in powder form. For busy people with more fruit than time, these special preparations are of real service to the home jam maker. They do all that is promised by the manufacturers and, though they may slightly increase the cost of the jam or jelly, I think some allowance must be made for the very definite saving in fuel, labour, and most importantly, time.
Remember that a glass marble swinging round at the bottom of the pan will help to keep the jam from burning. Add pure glycerine, stirred in 2 or 3 minutes before jam is ready to put up, will help to preserve it. One teaspoonful of glycerine for every 4 lb. of jam.
How to Test Jam for Set
When the jam appears to be thickening and a little hangs on the edge of the wooden spoon when held up, let the first test be made, but before doing so lower the heat, or draw back the pan to the side of the stove so that the preserve will continue to cook at a gentle simmer. Drop a spoonful of jam on a cold plate or saucer and stand it in the cool (a draughty window-sill is helpful). Give the test 5 minutes, tilt the saucer, and if the jam wrinkles a little and has a ‘crépy’ appearance it is ready, and can be potted up at once. On the other hand, if it shows still liquid and smooth, more cooking is called for. Raise the heat once more, and boil briskly for another 5 or 6 minutes before drawing once more to the side and testing a second spoonful.
It is always wise to reduce heat while testing, otherwise the jam may be over-boiled during the time taken up in the set. In a wet season, jam requires several minutes’ longer boil, to drive off the excessive moisture.
A small knob of butter added to jams is useful in imparting a brighter appearance to the preserve and in making scum easier to remove, as the butter aids in colecting it in one place. Butter papers, smeared over the bottom and just up the sides of the preserving pan before putting in the fruit, will make for greater safety against the preserve catching and burning. But care is still called for in adjusting the heat – jam making demands constant watchfulness.
When jam crystallizes it is not a problem, so it can be left undisturbed, but whenever a pot is required, just turn the contents into a small saucepan and bring nearly to the boil, then put into a clean pot. Excellent for present use and it is quite clear, but if stored would go sugary on the top again.
Sugarless Fruit-pulp for Jam-making
In the case of raspberries and other soft fruits, put the fruit into a preserving pan over very gentle heat until the juice begins to run, then increase the heat until the preserve is boiling; boil steadily for 45 minutes to 1 hour, stirring steadily. Continue to boil until you see the somewhat dry pulp draw away a little from the sides of the pan. Have your jars ready to go, they should be clean and dry and hot.