This is an age-old ratio for fruit jams: equal quantities of fruit to sugar, a little vanilla (omit it if you wish) and acidity in the form of a few teaspoons of lemon juice, whatever you get from one lemon. It’s a recipe that is easy to remember. It’s easy to adapt too by adding some crystallised or fresh ginger, cardamom seeds or even earl gray tea.
1kg rhubarb, washed, trimmed and cut into 1 inch pieces
1kg granulated or demerara sugar
Juice of 1 lemon
1 teaspoon vanilla extract (optional)
1. Toss the fruit with the sugar in a bowl and leave overnight, covered with cling film, to macerate.
2. When you are ready to make the jam place the fruit and any juices in a large heavy saucepan and add the lemon juice. Bring the mixture to the boil slowly over medium heat. Stir often until the sugar has dissolved. Keep boiling the mixture for an hour or so until it has thickened so much that the handle of a wooden spoon leaves a thick trail through the jam. Make sure that the jam doesn’t boil over (it is hell to clean up from the hob – if it does, mop it up immediately with moist paper towel) and keep stirring the mixture whenever you pass the saucepan. Five minutes from the end of cooking, stir in the vanilla extract.
3. We don’t bother testing for a set, if it’s soft we quite like it that way but if you want to, take a spoon of the mixture, place it on a cold out-of-the-freezer saucer and see if you can leave a trail in it when you run your finger through it. When it’s ready remove from the heat, leave to sit for a few minutes, then remove any white froth or scum from the top with a spoon or piece of paper towel. Pour the jam into warm sterilised jars, seal and leave to cool completely.
Rhubarb Jam Note
The rhubarb jam lasts up to a year if you pot it into sterilised jars and seal it correctly, though we often make smaller quantities and keep it as a quick jam in the fridge, covered in a bowl, where it lasts about a week.
Rhubarb and Ginger Jam Recipe | Add a spoon of finely chopped fresh ginger or one finely chopped crystallised ginger bulb with the rhubarb.
Earl Grey Jam | Add an earl grey teabag or a spoon of earl grey tea to 100ml boiling water. Leave to steep for 5 minutes, then strain and add with the rhubarb. You may need to boil the jam a little longer to thicken it.