Fruit-to-sugar ratio by volume 3:2
Fruit-to-sugar ratio by weight 5:4
4.5 lbs (2 kg) pitted and halved Blenheim apricots or 12 cups loosely packed 3.5 lbs (1.6 kg) granulated sugar or 8 cups 2 small lemons
1 Place prepared fruit in a ceramic bowl, add lemon juice and sugar. Cover with wax paper and macerate for several hours in the refrigerator.
2 Transfer mixture to a heavy enameled pot and slowly bring to a full boil.
3 Lower heat to a controlled boil, skim and continue to cook, stirring occasionally until mixture begins to reduce and thicken, and the apricot halves begin to break down. Check for a jell set at 20 minutesâ€”I went to about 22 minutes with this batch, which should give me a luscious consistency that will mound in a spoon but slowly drip through the tines of a fork.
4 Once the jam is sufficiently reduced, ladle into jars and seal. I processed the jars in a hot-water bath for 10 minutes, as suggested by Ball.
4.5 lbs apricots yielded a scant 6 pints of jam 1 x pint jar 5 x 8 oz jars 5 x 4 oz jars plus a few ounces set aside for breakfast.