Jams are a good way of storing surplus fruits for the winter. The preservation works by a combination of the boiling stage and the high sugar content of the product. Boiling kills micro-organisms and de-activates enzymes and sugar inhibits the growth of bacteria that may contaminate the jam later. You can also make low sugar jam but it will be runnier and will need to be kept in the fridge and will not store for so long as the one with a higher level of sugar.
When making jams choose fruits that are just ripe or nearly ripe because over-ripe fruits have little pectin and will make a runny jam. Chop the fruits and add them to a large pan. Heat them and simmer for 15-45 minutes depending on what fruits you are using. Add the sugar, 60% by weight. Stir well to dissolve the sugar then bring back to the boil and stir as little as possible. Boil hard until setting point. Remove from the heat immediately, skim off any scum from the surface then stir and ladle the jam into sterilized jars which have been warmed in the oven.
Jellies are essentially jams made out of the fruits juice. They should be clear, bright-colored and packed with flavor. You need something to strain the fruit pulp, a purpose-made jelly-bag or a piece of nylon or muslin and something to support the straining bag over a collecting bowl. Always boil the muslin bag before and after use.
After cooking the fruits to a pulp ladle it into the straining bag and leave until the juice has stopped dripping through. Do not push or squeeze the bag, as slow straining is essential for a clear jelly. Pour the juice into a pan, bring to boil and add the sugar, 600 g to 1 kg of sugar to 1 liter of juice, depending on pectin levels of the fruits you use. Stir to dissolve the sugar and bring back to the boil, then stir as little as possible. Boil hard for 10 minutes then test for setting point. When setting point has been reached remove the pan from the heat immediately, skim off any scum from the surface then stir and ladle the jelly into sterilized jars which have been warmed up in the oven.
Cool, label and store the jams and jellies.
