I prepare the juice in the juicer without adding water. 1.5 kg of currants make about 1 liter of juice in my steam extractor. If you don`t have a juicer, you can carefully boil the berries and then let them run through a cloth. Takes a little longer and the currants have to be stalked beforehand.
Heat the canning sugar in a large saucepan until it caramelizes slightly. Be careful not to turn it too brown, as this will quickly turn bitter. It should only turn light brown. Now pour in the currant juice and the juice of the two lemons. Be careful it splashes! Cook the juice while stirring. Make a gelling test after approx. 10 minutes. Simply pour a drop onto a plate with a spoon. Usually 10 minutes are enough, but it depends on the degree of ripeness of the berries. I always pick the berries for the jelly as soon as they turn red. The more ripe the berries, the lower the pectin content and then it can take a little longer.