Calculate how much sugar and pectin you need for berries or fruit, whether you're making quick or traditional jam.
Quick jam uses more sugar and added pectin, with a short cooking time. This lets the jam keep more of the color and fresh taste of the raw fruit. Traditional jam uses less sugar and longer cooking, which gradually thickens the jam without added pectin — this works especially well for berries and fruit that are naturally high in pectin, like currants.
Berries and fruit with naturally high pectin content, like currants and apples, thicken more easily on their own with long cooking. Berries with less natural pectin, like strawberries and raspberries, often need added pectin to thicken quickly in the quick method.
Quick jam uses more sugar and added pectin with a short cooking time, and keeps more of the color and fresh taste of the raw fruit. Traditional jam uses less sugar and longer cooking, which gradually thickens the jam without added pectin.
Some berries and fruits, like currants and apples, are naturally high in pectin and thicken easily on their own when cooked. Others, like strawberries and raspberries, have less natural pectin and often need added pectin to thicken well, especially with a short cooking time.
Sugar doesn't just affect sweetness, but also texture and shelf life, since sugar binds water and inhibits bacterial growth. If you reduce the sugar a lot, follow a recipe or product specifically designed for low sugar, and store the jam refrigerated.