For the currant cake jam, place the grated currant – I always mix red and white, but it works with red or white alone – in a large saucepan.
Using a potato masher or similar device, mash the currant, then bring to a boil over high heat, stirring. Remove from the heat and patiently strain the entire mass through a float with the smallest of holes.
Bring the strained mass to a boil with the preserving sugar and cook for about three minutes.
Then, with the help of a funnel, pour it into jars, screw them shut and let them cool.
Since the currant cake jam has only half as much sugar as fruit pulp, it will only keep for about 1 year. I use this jam for Linzer cakes, so it’s just right there.
We don’t like seeds in the jam, and the jelly melts on the linzer dough, so you need just this jam.