Making jam and preserves
The recipe is the easy part. The jars and the seal are what make it keep, and getting those right means even a rough batch is safe months later.
18 items
Makes your own editable copy. No account needed.
The items
- Fruit at its ripest, not a day past itA few slightly under-ripe pieces mixed in help it set — ripe fruit alone has less pectin.
- Jam jars, sterilised×8
- Lids that actually sealA dented or scratched lid won't seal however clean it looks. Check each one before filling it.
- Sugar — the full amount the recipe calls forCutting it back to make jam 'healthier' is what causes mould after three weeks. It's a preservative here, not just sweetness.
- Lemon juice or citric acid, for low-pectin fruit
- A sugar thermometerSetting point is 105°C. A thermometer takes the guesswork out of the plate test.
- Large, heavy-bottomed pan, bigger than looks necessaryJam rises hard as it boils. A pan that looks generously sized still boils over if it's only just big enough.
- Jam funnel
- Wax discs or waxed paper, if not using a full water bath
- Labels and a pen that doesn't smudgeFruit, and the year. 'Jam' on its own is a mystery by March.
- Wooden spoon, and a saucer kept in the freezer for testing the set
- Muslin or a jelly bag, for jelly rather than jam
- Vinegar and spices, if preserving vegetables as a chutney rather than fruit
- Splash guard or a taller pan, for anything that spits
- A plan for a batch that doesn't setRunny jam isn't a failure — it's a sauce for yoghurt or a cake filling. Rebottle it as that instead of binning it.
- Somewhere cleared to cool jars, out of a draughtA hot jar cracking against a cold surface is usually a draught, not a faulty jar.
- Somewhere dark and cool to store sealed jarsLight fades the colour and heat shortens the shelf life — a cupboard, not a sunny windowsill.
- Checking the seal before eating something months laterA lid that's popped up, or a jar that fizzes on opening, means something's got in. Bin it without tasting it to check.
Makes your own editable copy. No account needed.
Questions people ask
- How do you know jam has reached setting point?
- Put a teaspoon on a cold plate, wait a minute, then push it with a finger. If it wrinkles, it's set. A sugar thermometer reading 105°C is the same test with a number.
- Why did a jar go mouldy after a few weeks?
- Usually an underfilled jar, a loose lid, or fruit left uncovered by syrup. Sterilise properly, fill to the top, and a sealed jar should keep for a year unopened.
- Can old jam jars be reused?
- Yes, if the lid still seals — a dented or scratched one won't. Wash and sterilise in a hot oven or boiling water, then check the seal before trusting it.