Has anyone had trouble getting strawberry jam to set? I know I have. I’ve tried adding a couple of Granny Smith apples, and this helps, but this year I have developed a new way to ensure a good set. It is by the simple addition of a little tartaric acid. For each 500g strawberries, you need to add three quaters of a teaspoon of tartaric acid (at the outset of cooking).
Tartaric acid, by the way, is a natural food acid found in many fruits. It can be purchased from supermarkets (usually near where baking powder is found).
Strawberries are not high in acid, nor in pectin, both of which are needed for a jam to set well. Adding the tartaric acid increases the acid level, as well as helping to extract the pectin. I first tried this with some strawberries that were going to waste in punnets in the fridge. Pectin levels drop the longer a fruit is off the bushes or tree, and these would have been at least a week old, so the odds were against the jam setting.
However, much to my amazement, it set perfectly, as had every batch I’ve made since. The recipe is here for you to try. You can double the recipe but no more – large batches of any jam mean longer boiling. This causes the sugar to caramelise and then the jam is dominated by this rather than the beautiful flavour of the fruit.
500g strawberries, hulled
Three quarters teaspoon tartaric acid
Quarter cup water
Chop the strawberries roughly and place in a medium saucepan with the tartaric acid and water. Bring to the boil and simmer gently for 10 minutes. Add the sugar and stir util dissolved. Bring the jam to the boil and boil over medium heat for 20 minutes.
Pour into sterilised bottles and seal immediately.
To prevernt he discoloration of the jam, or any jam for that matter, store the cooled jars of jam in the freezer – truly. It is very cold when yu take it out, but not frozen. The sugar content prevents the jam from freezing and it keeps its lovely bright sharp colour and flavour.