wild blackberry jam

Wild blackberries contain a lot of seeds and ripen unevenly, so take care to avoid a coarse texture in the finished jam.

Picking

1. Wear latex gloves (use talcum powder to help put them on) and clothes you do not save for special occasions, unless the special occasion is charging into a swarm of bees.
2. Pick only ripe blackberries. Discard any plant debris.

Method

1. Chill the fruit in the fridge for a few hours.
2. Wash it gently, remove the stalks and any other plant debris, then leave to drain.
3. Place the fruit in a large saucepan, add the lemon juice and brown sugar and mix. Leave to stand for 1 hour to allow the fruit to release its juices.
4. Place the saucepan over the heat and cook, stirring occasionally, until the fruit comes to the boil.
5. Remove the saucepan from the heat and pass the mixture through the food mill.
6. Collect the strained liquid in the saucepan.
7. Add a small amount of boiling water to the pulp and seeds left behind and blend to a purée. Pass the purée through a fine-mesh sieve using a small whisk, then add it to the saucepan.
8. Weigh the purée to calculate the amount of gelling agent required.

   You can calculate the exact amount using this tool.

9. Return the saucepan to the heat. Add the gelling agent and stir until the mixture comes back to the boil.
10. Check the setting point: place a teaspoonful of jam on a plate. Run your finger through the centre; if the two sides remain separate and do not flow back together, the jam is ready.

Storage

1. While the jam is still very hot, divide it between airtight glass jars.
2. Seal immediately and turn the jars upside down while they cool. This helps create a vacuum, although this is not guaranteed unless the filled jars are boiled.

Properly sealed, the jam will keep for months at room temperature.