A nice and easy method for jam making. I have tons of cherries on my tree and I hate the mess you make when you pop them from raw, so here goes.
Start with a kilogram of dark cherries, whole, pips in, tails off. Put them in a tall pot with a glass of water. Cook them gently until the fruit is completely soft. This is the trick: cooking them whole first means you lose nothing. All the dark juice, all the depth, stays in the pot. You can do this the day before and leave them in the fridge until you are ready.
When they are cool enough to handle, remove the pips. Your hands will be stained and the kitchen will smell extraordinary. That is as it should be.
Put the fruit and all its liquid back on the heat. Add 700g of white caster sugar and stir as it melts. Grate one tonka bean directly into the pot, they are very hard; use a fine microplane and do it slowly. One bean for one kilogram of fruit. You can also leave it whole to infuse, but try to remove it before you pot the jam (it's a bit like a treasure hunt, so see how patient you feel). The tonka will give the jam a whisper of vanilla and almond that makes it feel ancient, like something that was always made this way.
Let it bubble, not a hard boil, a steady bubble, for about twenty-five minutes. Stir occasionally. Taste it. It should be deep and dark and warm.
When you are ready, add a sachet of pectin dosed for your quantity of fruit and stir quickly, the jam will rise in the pan, so watch it. Boil, then off the heat.
Have your jars ready. They need to be sterile so super clean, I give mine a good dishwasher wash and let them dry just before use.
Ladle the hot jam in immediately, fill to within five millimetres of the top, and seal the lids right away. Set them aside and listen. As they cool you will hear the lids pop, one by one, as they seal themselves shut.
Tonka beans contain coumarin and should not be eaten in very large quantities. They are perfectly safe at small doses and widely used in European patisserie. If you cannot find them, you can add a drop of almond essence, but the jam is still worth making without any additional flavours.
