Blackcurrants are generous fruit. Their skins and pips carry plenty of natural pectin, and the juice is sharply acidic, which is exactly what a jam needs to firm up. That means you can make a proper, glossy blackcurrant jam with nothing more exotic than fruit, sugar and a splash of water. This small-batch version makes two or three jars — ideal for a first attempt, a modest hedgerow haul, or a pan you can actually lift.

Why blackcurrants set so readily

Pectin is the gelling agent in fruit, and it needs two things to do its job: acid and sugar. Blackcurrants arrive with both built in. The acid comes free in the juice, and the pectin sits mostly in the skins and pips, so there is no need to add a commercial setting agent, lemon juice or apple.

One point worth knowing: ripeness matters. Berries that are fully black but still a little firm hold the most pectin. If you pick late, when the fruit is soft and squashy, the set will be slower and looser. A handful of slightly under-ripe berries in the pan is a genuine help, not a compromise.

What you need

This recipe makes roughly 600g of jam — two standard 300ml jars, or three smaller ones. Keep the proportions if you scale up, and remember to keep the batch small: a large pan of jam takes longer to reach setting point, which dulls the flavour.

• 500g blackcurrants, fresh or frozen. No need to thaw frozen fruit.
• 500g granulated sugar. Preserving sugar works well too. Do not use jam sugar with added pectin — it will set too hard.
• 150ml water, or 100ml if the fruit is frozen.
• A small knob of butter, about 10g, to settle the foam (optional).
• Equipment: a heavy-based saucepan, a long wooden spoon, a jam thermometer if you have one, a saucer in the freezer, a ladle or wide funnel, and sterilised jars with clean lids.

The method, step by step

1. Prepare the fruit. Strip the berries from the stalks with a fork — far quicker than picking them off by hand. Rinse and drain. You do not need to top and tail them; the stalks come away with the stripping and any stray bits are caught when you skim.
2. Soften before sweetening. Put the fruit and water in the pan and bring to a gentle simmer. Cook for 10 to 15 minutes, stirring now and then, until the skins have burst and the fruit has collapsed into a rough pulp.
3. Add the sugar off the heat. Tip it in and stir until every grain has dissolved. Warmed sugar dissolves faster, so a few minutes in a low oven is a sensible habit. Rub a little of the liquid between your fingers: if it feels grainy, keep stirring.
4. Boil hard. Turn the heat up and let the jam bubble vigorously for 8 to 12 minutes, stirring occasionally so it does not catch. Small batches can climb the pan, so stay nearby.
5. Test the set at the eight-minute mark, then every couple of minutes after that.
6. Finish and pot. Skim off the foam, stir in the butter if you are using it, then leave the pan to settle for 10 minutes. Stir once and ladle into warm, sterilised jars.

Testing the setting point

A jam thermometer takes the guesswork out of it: setting point is roughly 104–105°C. If you would rather trust your eyes and fingers, the saucer test is reliable once you have done it a few times.

The saucer test

Drop a teaspoon of jam onto a cold saucer from the freezer and put it back for a minute. Push the blob with your fingertip. If the surface wrinkles and the jam holds its shape instead of running, it is ready. If it slides about, boil for another two minutes and try again. Take the pan off the heat while you test, so you do not overshoot.

The flake test

Lift a spoonful and let it cool for a second, then tip it back into the pan. At setting point the jam falls in a thick sheet or flake rather than in thin drips.

If something goes wrong

• Still runny after cooling. Tip the jam back into the pan, bring it to a hard boil for two or three minutes and retest. This is why it pays to pot one jar at a time — you can catch a loose batch before it is all sealed.
• Set like glue. Usually too much sugar or a long boil. Loosen it in the pan with a splash of water and reboil briefly, or simply use it warmed as a sauce over yoghurt or ice cream.
• Fruit floating at the top. The jam was potted too soon after boiling. Resting it for 10 minutes and stirring once before filling keeps the fruit evenly spread.
• Sharp, grippy flavour. Blackcurrants are acidic by nature. A slightly higher proportion of sugar, up to 550g, softens the edge without affecting the set.

Jars, lids and storing

Wash jars in hot soapy water, rinse well and dry them in a low oven at about 140°C for 15 minutes. Lids usually fare better in a bowl of just-boiled water than in the oven, especially if they have a plastic coating inside. Fill the jars while both jam and jars are hot, leaving a centimetre of headroom, and seal straight away.

Once opened, keep the jar in the fridge and use it within a few weeks. Unopened, the jam will keep somewhere cool and dark for up to a year, though the colour fades with time.

Picking, freezing and a final note

Hedgerow blackcurrants are usually ready from mid-July into August. Pick in dry weather, early in the day, and taste as you go: the best jam comes from fruit you would happily eat raw. Surplus berries freeze beautifully on a tray and then into bags, and frozen fruit makes this jam just as well — simply use the smaller amount of water.

One last habit worth adopting: write the date and the fruit on the label, and note how long you boiled the batch. Next summer you will know exactly where to start.

Photo: congerdesign / Pixabay