Making Seasonal Fruit Jam Without Pectin

Start with fruit at its peak

Good jam begins in the hedgerow, the allotment or the pick-your-own field. The single most important rule is to use fruit that tastes excellent raw. Sugar cannot rescue bland, watery berries; it simply makes them sweeter and bland. Pick on a dry day once the dew has lifted, and use the fruit within a day or two, or freeze it in weighed bags until you have time.

Rinse gently and pick over carefully, discarding stalks, leaves and any bruised or mouldy fruit — a single furry strawberry can taint a whole batch. Hull strawberries, stone cherries and plums, and strip currants from their stems with a fork. If you are using rhubarb, chop it into short lengths. Large fruit can be halved or quartered, but leave small berries whole so the finished jam has texture.

The simple ratio: fruit, sugar, lemon

You need no pectin powder for most summer preserves, just the right balance of fruit, sugar and acid. As a reliable starting point, weigh 1kg of prepared fruit and allow 750g to 1kg of ordinary granulated sugar. Soft, juicy fruits such as strawberries and raspberries sit at the lower end; sharper fruits such as blackcurrants, damsons and gooseberries take the higher amount.

Acid is what helps the natural pectin in the fruit set. Add two tablespoons of lemon juice per kilogram for low-pectin fruits — strawberries, raspberries, cherries, elderberries and rhubarb. Blackcurrants, gooseberries, plums and apples contain plenty of their own and need little or none, though a squeeze never hurts. If you can, toss the fruit and sugar together in a bowl, cover and leave overnight. The sugar draws out the juice, so the jam cooks faster and tastes fresher.

How to read the setting point

Tip everything into a wide, heavy-based preserving pan — a wide pan evaporates faster than a deep one — and warm gently until every grain of sugar has dissolved. Stir with a wooden spoon, and once the liquid is clear, turn up the heat and boil hard.

Start testing after about ten minutes. The easiest method is the saucer test: put two or three small plates in the freezer before you begin, then spoon a little jam onto a chilled plate and leave it for a minute. Push it with your fingertip. If the surface wrinkles and the jam holds its shape rather than running, it is ready. Alternatively, use a jam thermometer — the setting point is roughly 104–105°C — or lift a spoonful and let it drop back; at setting point it will fall in a flaky sheet rather than a thin stream.

• Too runny after cooling? Return it to the pan with a little more lemon juice and boil again for five minutes.
• Too stiff or crystallised? You probably boiled too long or stirred once the sugar had reached setting point.
• Scum on the surface? Skim it off with a slotted spoon, or stir in a small knob of butter at the end.

Sterilising jars and lids

Clean jars are non-negotiable; this is what keeps your preserves safe for months. Wash jars and lids in hot soapy water, rinse well, then sterilise them in one of three ways. The oven method is the most dependable: stand clean jars upright on a baking tray and heat at 140°C (fan 120°C) for 15 minutes. The dishwasher method works if your machine has a hot rinse — leave the jars inside until you are ready to fill them. Or boil jars and lids in a large pan of water for ten minutes.

Metal lids with a rubbery sealing ring can simply be boiled for ten minutes and left to drain on a clean tea towel. Handle everything with clean tongs or oven gloves, and never dry the inside of a jar with a cloth — that is how you reintroduce bacteria.

Potting, sealing and storing safely

Fill jars while both jam and jar are hot, using a jug or a jam funnel. Leave about 5mm of headspace, run a skewer around the inside to release trapped air bubbles, and wipe the rim with a clean damp cloth. Screw the lid on firmly while the jam is still hot: as it cools, the lid dips inwards and creates the vacuum seal that protects your work.

Leave the jars undisturbed for twelve to twenty-four hours before checking. A properly sealed lid curves downwards and gives no click when pressed. Label with the fruit and the date, then store in a cool, dark cupboard for up to a year. Once opened, keep the jar in the fridge and use it within three to four weeks. If you ever spot mould on the surface, discard the whole jar — do not simply scrape it off, as invisible threads may run through the jam.

Small twists and quick fixes

Once you are confident with the basic method, vary it freely. A vanilla pod simmered with the fruit, a few sprigs of rosemary or thyme, a splash of ginger, or a tot of whisky all lift a jar from good to memorable. Strawberry and rhubarb, raspberry and rose, blackberry and apple, plum and star anise — the combinations shift with every week of the season.

Make small batches often rather than one enormous one; they set faster, taste brighter and make far better gifts. And keep a jar for yourself, opened on a grey January morning when a spoonful of August is exactly what the kitchen needs.