Which Fruit to Choose

Choose firm just-ripe fruit for making jam, as overripe fruit lack the pectin needed for setting. Some fruit are quite low in pectin, such as blackberries, cherries, figs and nectarines, or have none at all and need the addition of pectin-containing fruit (such as apples or citrus fruit) or juice or commercial setting agents to help them set.

The acidity of the fruit acts as both a preservative and a setting agent. Fruit that have low acid levels, such as apricots, figs, kiwi fruit, strawberries and pears, can be supplemented with lemon juice or by adding fruit that are high in acid, such as cherries, blackberries, blackcurrants, citrus or green apples.