Raspberry jam is the easiest jam there is, and one of the best. Raspberries are full of natural pectin and acid, so they set beautifully with just sugar and a short, sharp boil, no shop-bought pectin needed.
The only rule is not to over-boil it, because that's what spoils the set and dulls the colour. The recipe is below, with more on why raspberries are so easy to work with underneath it.
How to Make Raspberry Jam: An Easy UK Recipe
Makes About 3 × 340g jars
Prep
10 min
Cook
20 min
Total
30 min
Makes
About 3 × 340g jars
Ingredients
Fruit & acid
Sugar
Optional
Method
- 1
Put a couple of saucers in the freezer, sterilise your jars, and warm the sugar in a low oven so it dissolves quickly.
- 2
Warm the raspberries in a wide pan over a low heat, crushing them lightly, until the juices run.
- 3
For seedless jam, push some or all of the warm pulp through a fine sieve at this point.
- 4
Add the warmed sugar, and the lemon juice if using, and stir over a low heat until every grain has dissolved.
- 5
Raise to a full rolling boil and boil hard for about 5 minutes. If you're using jam sugar, this is nearer 4 minutes.
- 6
From 4 minutes in, start testing: spoon a little onto a cold saucer, wait a minute, then push it. A wrinkled skin means it's set, or 104 to 105°C on a thermometer.
- 7
Take the pan off the heat, stir in the butter if using, and rest for 5 to 10 minutes so the fruit suspends evenly.
- 8
Pot into hot sterilised jars, seal, and label.
Cook’s notes
- Raspberries are a medium-to-high pectin, high-acid fruit, so they set on their own; there's no need for shop-bought pectin, and often no need for lemon either.
- Keep the boil short. Overcooking breaks the pectin down and gives a worse set and a duller colour, so start the wrinkle test early.
- The lemon is insurance, not a rule. Leave it out with a dead-ripe, high-pectin crop; add it if the berries are very ripe or the set looks lazy.
- Freezer-jam option: mash raw berries with the sugar, leave until dissolved, then freeze. It's a fresher, looser preserve that skips the boil entirely and keeps about a year frozen.
- Sterilise jars in a hot oven or a hot dishwasher cycle, and pot the jam hot into hot jars for a good seal.
What you’ll need
- Wide preserving pan
- A couple of saucers, chilled, for the set test
- Fine sieve, optional, for seedless jam
- 3 warm sterilised jars with lids
Troubleshooting
The jam is runny.
Re-boil it with the juice of half a lemon until it wrinkles on a cold plate; the acid releases the pectin.
It set rock hard.
Stir in a little just-boiled water to loosen it. Next time, stop the moment it wrinkles.
There's scum on the surface.
Stir in a small knob of butter off the heat, which disperses it.
The fruit floated to the top.
Rest the jam for 5 to 10 minutes and stir once before potting.
It went mouldy in storage.
Damp or under-sterilised jars, or a poor seal. Re-sterilise and always pot hot jam into hot jars.
More about raspberry jam
Why raspberries are so easy. Raspberries are a medium-to-high pectin, high-acid fruit, which means they carry both of the natural setting agents jam needs. That's why they set with nothing but sugar, and why most recipes skip added pectin and often lemon too.
It's a quick-set jam. Setting point at 104 to 105°C arrives after just four to eight minutes of hard boiling, far faster than low-pectin fruits like strawberry or cherry. Watch it closely from the start.
Why less sugar works. Because you don't need extra sugar to force a set, a ratio nearer four parts fruit to three of sugar gives a fresher, brighter, more fruit-forward jam that still keeps well. The old one-to-one rule was really about maximising shelf life.
Don't over-boil. Pectin degrades with prolonged heat, so a long boil actually undermines the set and browns the colour. Short and sharp wins every time.
If you do want help. A lower-sugar batch can lean on jam sugar, which has pectin blended in, or a squeeze of lemon, which adds the acid that frees the fruit's own pectin.
Frequently asked questions
Written by
UK Homesteading Team
Editorial team
The UK Homesteading editorial team, offering UK-specific, evidence-led guidance on growing, keeping, preserving and the law.
