Makes 2 pint jars
Pectin is found to varying degrees in fruit, but is particularly high in the skin, membranes, and seeds. Further, pectin is especially high in apples and citrus. Young, unripe fruits are particularly pectin-packed! The “green” in the recipe refers to this—unripe fruit. You can make your own pectin at home and add it to your low-pectin preserves (some berries, cherries) to help with the “set” of the jam. It’s a great shortcut that you can do all by yourself—a very DIY project for the summer, as apple trees are just setting their fruit.
SUGGESTED VARIETIES: Any undeveloped green apple picked from the tree before ripening.
3 pounds unripe apples, stemmed and quartered
6 cups water
Juice of 1 small lemon
4½ cups sugar
Put the apple pieces in a large stockpot and cover with the water. Bring to a boil then reduce the heat, simmering for 30 minutes. Strain this apple mixture through a fine-mesh strainer, pressing lightly on the back of the fruit. Discard the solids and reserve the liquid.
Set a mesh strainer over a large bowl and line with 4 layers of moistened cheesecloth. Filter the apple liquid again through the cheesecloth, resulting in a mostly clear liquid.
Measure out 4¼ cups apple liquid and add to a saucepan with the lemon juice and sugar. Bring to a boil, skim the foam, and cook on high heat for about 10 minutes. You want a thick, syrupy or jammy set. Put the apple pectin in clean, sterilized jars leaving ¼ inch head space. Using a damp clean towel, wipe the rims of the jars, and top them with lids and rings. Process in a water bath for 10 minutes. Remove the jar with tongs and let it cool on the counter. Once it’s cool, make sure the seal is secure. A sealed jar may be stored in a cool, dark cupboard for up to 1 year. You can also hold it in the fridge, where it will keep for several months.