The raspberries are boiled with the sugar and some of the water until the sugar is dissolved and the pulp is very soft. This takes 5 to 8 minutes. (If you want to reduce the sugar or leave it out completely, you can do it according to your taste.)
Then the mass is passed through a fine sieve and set aside until it has cooled down a bit.
The citrus fruits are simply squeezed and the juice is poured into a large glass carafe. When the raspberry juice has cooled down, add it and the whole thing can be poured over with the rest of the cold water.