It’s unlikely i’ll ever buy standard jam again. Once you know how its made, its hard to justify store-bought because it is so easy. Here is a template you can use to make any jam.
wash berries
‘Pectin’ is what makes a jam thick. This is naturally found in some fruit. Apples are high in pectin, and so are lemons. Ripe berries are not. So if you use blackberries, pick some in various stages of ripeness, the unripe ones have more pectin in them, meaning your jam will be thicker
Add sugar
I won’t give an exact measurement because it depends on how sweet you like your jam, how sweet the fruit is that you’re using. Start with 1 cup and see it needs more later.
VARIOUS STAGES
The volume has reduced as the water evaporates…
You can see here how thick this jam is becoming. When you turn it off, it will thicken some more, so turn off a little runnier than you’d like the final jam to be
FROZEN BERRIES
Frozen berries are perfect for making your own compote or jam. Note that because there isn’t any preservative, this will last only a few weeks in the fridge.
*QUICK GUIDE:
Jelly = fruit juice + sugar + gelatine
Jam = chopped or pureed fruit + sugar + pectin
Chutney = chopped or pureed fruit + sugar + vinegar + spices
Preserves = whole fruit or fruit chunks + sugar
Marmalade = whole citrus (either chopped or left intact) + sugar
Compote = whole fruit or fruit chunks + sugar (but usually eaten immediately, not preserved)