Blackberry jam

Method

1. Rinse the blackberries briefly. If you do not like the seeds, push the jam through a sieve after cooking.
2. Mix the fruit with the sugar and lemon juice and leave it for a few hours or overnight to release its juice.
3. Cook over a medium heat, stirring and skimming, for 20 to 40 minutes, until a drop of jam on a cold saucer stays put when you tilt it.
4. With 2:1 jam sugar four minutes of boiling is enough; use half a kilogram of it per kilogram of fruit instead of ordinary sugar.
5. Pour the hot jam into sterilised jars to the brim, close them and turn them upside down for five minutes.

When to make it

Best: August. Possible: July, August, and September.

October: Out of season.

How we count

1 kg (Blackberries) makes about 0.95 l.

Blackberries have no waste; if you sieve out the seeds, count on about 15% less. With half a kilogram of sugar per kilogram of prepared fruit you get about 1.3 kg of jam, and a litre of jam weighs about 1.3 kg: roughly a litre per kilogram of prepared fruit.