Making your own jam – a bit like making your own bread, or your own butter – feels like conjuring something from nothing. Just three ingredients, a pot and maybe a thermometer, and you have a delicious spread for months to come.

For many, what puts them off jam making is the fear of a massive cauldron of bubbling, dangerous syrup. However, there’s no need to make more than a couple of jars at a time if you don’t want to. Although jam was historically used to preserve a season’s fruits and vegetables, making small batch jam is a great way to sample lots of different fruits. The recipe below uses just 600g fruit, and makes enough to fill two jars of jam.

The ratio of sugar to fruit in jam varies quite a lot. The traditional ratio is 1:1 by weight. So, 300g fruit to 300g sugar. This higher proportion of sugar gives you a firmer set and, naturally, a sweeter jam. For a looser set and a less sweet taste you can go down to as low as 2:1 fruit to sugar (so 300g fruit to 150g sugar), but if you go much lower than this your jam won’t set at all.

Frozen berries are brilliant for making jam, particularly out of season. For the recipe below, you don’t need to defrost them – just mix the berries with the sugar and lemon juice while frozen then follow the rest of the recipe.

One of the trickiest parts of making jam is getting the set right. Our recommendation is to always use at least two methods of checking the set of your jam – the temperature, and the wrinkle test. Without a thermometer, it can be quite difficult to know when to do the wrinkle test as a beginner. But, equally, without the wrinkle test sometimes jam can come to temperature but not quite be set. 

The setting point of jam is 104°C–105°C. It’s easiest to take this reading with an instant-read digital thermometer, since even a few degrees over can lead to overboiled jam. Once it’s at this point, take it off the heat, and put a small spoonful on a chilled spoon or bowl. Place the spoonful back in the freezer and chill for 5 minutes or so.

Once chilled, check to see if it forms a few little wrinkles when you nudge it with your finger. If it does, then it’s set. If not, return the pot to the heat and hold at 104°C for at least a couple of minutes, then check again.

Jam can take a surprisingly long time to fully set after cooking. If it’s still looking runny after a few hours, especially at room temperature, don’t fret. We’d recommend chilling the jam in the fridge and waiting at least 24 hours before determining it isn’t set.

If after 24 hours it’s still loose, you can simply return it to the heat and bring it back to temperature and do the wrinkle test again. You’ll need to sterilise all of your jars again before returning the jam to them.

The recipe below isn’t designed to be shelf stable – there’s no canning, and the jam should be kept in the fridge instead. However, it is designed to be fairly long lasting, so it’s important that everything that touches the jam is clean. This includes the pot and the thermometer, but also, of course, the jam jars.

We recommend that you wash the jars and their lids in hot soapy water, and then place them on a tray and heat in a 120°C fan oven for 20 minutes.

You will need two sterilised jars and an instant read thermometer for this recipe.

This jam will keep well in the fridge for a few months, but make sure to always use a clean spoon when getting any jam out of the jar.

You may have seen jam sugar next to the cane sugar in the supermarket, and wondered ‘do I really need that to make jam?’ The short answer is no, you don’t, but the long answer is a bit more complicated.

Jam sugar is a combination of sugar and pectin. Pectin is what helps jam set. It’s found naturally in fruit, but in varying levels. Some fruits, like gooseberries have a lot, while other fruits, like strawberries have barely any. Pectin levels also decrease as fruit ripens, so although overripe fruit might look more ‘jammy’, it isn’t actually as good for jam as fruit that’s a little bit underripe.

Using jam sugar gives you a consistent amount of pectin in your jam, and makes the jam much firmer than using no pectin at all. However, so long as you cook your jam to the right temperature, and make sure it passes the wrinkle test (more on that below) it’s not necessary. 

If you do like a firmer set to your jam, feel free to swap out the sugar in our recipe for jam sugar.