Making my own perfect jam

© Thinkstock

To make jam successfully, you not only need to know which fruits to choose, the right ingredients and have the right equipment, but you also need to have mastered the technique.

Here’s a step by step guide from Christine Ferber, known in France as the "the queen of jam".

Making the perfect jam: the right ingredients

"To make a good jam, you need to choose healthy fruit which is just ripe and full of flavour," advises Christine Ferber. If fruit is a bit overripe, it‘s better to make a fruit compote instead. Overripe fruit will have less acidity, the natural pectin in the fruit will react less and the fruit will puree so you won’t get those lovely juicy chunks in your jam. Make the jam soon after buying or picking the fruit.

You will need good quality, white granulated sugar that is dazzlingly white. "Some people use cane sugar, which gives a caramelised, vanilla flavour," Christine Ferber says. It’s a question of taste. Our specialist does not use this however, as it doesn’t preserve as much of the fruit’s colour during cooking. You also need lemon juice: it brings out the fruit’s flavour, preserves the taste and encourages the jam to set, as well as preserving it without the sugar in the jam becoming crystallised.

Making the perfect jam: suitable equipment

As for equipment: in addition to classic scales, measuring cup, squeezer, colander, chopping board, knife and peeler, get a saucepan ready or, better, a copper bowl, a wooden spoon for stirring the jam, a slotted spoon for taking off the foam when the jam starts to boil, ladle, and lastly, some jars and lids. You might also want a funnel for putting the jam into the jars.

Do you need a gelling agent as well? "I don’t really like to add a gelling agent or sugar with added pectin as these can sharpen the taste a little," Christian Ferber explains. Instead she advises adding fruit naturally rich in pectin* to jams made out of fruit that’s low in pectin: for example one part redcurrants, blackcurrants or raspberries mixed in strawberry, or cherry jam.

You can also use the following technique: cook the fruit with sugar on the first day, take the fruit out and then the next day boil the liquid adding the pieces of fruit back to the mixture.

Making the perfect jam: helpful tips

"To successfully make jam, you need to follow the recipe rigorously," insists Christine Ferber. Once you have truly mastered the technique, you can then start using your imagination and invent new recipes!The first golden rule is making sure you get the right proportion of sugar and fruit. You need 800g of sugar to 1kg of fruit for making jam and 1kg of sugar for 1kg of fruit to make a jelly. Jams with less sugar do not keep as well. Use a maximum of 4kg of fruit for cooking. Then mix the fruit, sugar and the juice of half a lemon before cooking the jam.

Cooking time depends on the fruit used. Bring it to boil whilst stirring the mixture all the time, lifting the foam off. The way to tell when the mixture is cooked is to use a sugar thermometer: the temperature must be 105°C. If you don’t have a thermometer, put a few drops of jam on a cold plate: it must set slightly.

Christine Ferber has a few more tips for telling when the jam is cooked: the jam must not have any more foam on the surface and the fruit should stay submerged in the syrup and bubbling should be less intense. For some types of jam, it’s necessary to soak the fruit with sugar and lemon juice overnight, or even cook it twice. There is no secret to finding out the best techniques for cooking your jam, just check the recipes written by the pros!

Storing your perfect jam

The best method of storing jam is to use glass jars with screw tops. Sterilise the jars and lids by putting them in a pan of boiling water or putting them in a hot oven. Leave them to dry on a clean cloth. As soon as the jam is ready, fill the jars to the brim and put the lids on, screwing them tightly. Put the closed jars upside down until they have cooled down completely: this will limit the amount of oxygen getting inside the jar.

Christine Ferber’s little tip is never to reuse the lids: after a few uses, the seal stops working as well. If your lid is not completely airtight, there is a risk of getting mould in your jam. Keep jars out of sunlight, in a cool, dry place.

UK-grown fruits, season by season…

• January: apples, pears, tangerines

• February-May: have a rest and enjoy the jams you made over the other months!

• June: gooseberries, cherries, elderflowers, raspberries, strawberries, tomatoes

• July: blueberries, cherries, gooseberries, greengages, loganberries, raspberries, redcurrants, strawberries

• August: bilberries, blueberries, greengages, loganberries, plus, raspberries, redcurrants

• September: apples, bilberries, blueberries, damsons, grapefruit, pears, plums, raspberries, redcurrants

• October: apples, bilberries, blackberries, elderberries, medlars, pears, plums, quince

• November: apples, elderberries, medlars, quince

• December: apples, pears, tangerines

Source: eat the seasons

* Pectin-rich fruits: raspberries, gooseberries, blackcurrants, quince. Pectin-poor fruits: strawberries, cherries.

Anne-Sophie Glover-Bondeau

More information:
Blueberry jam
Strawberry jam
Nutrition discussions