2,2 lbs (2 kg) of rhubarb
2 3/4 cups (6,5 dl) cane sugar
6 1/3 cups (1,5 l) boiling water
Flavor it with i.e. a cinnamon stick or two, lime (2-3), lemon (1-3) and/or a little vanilla. This time I used two lemons one cinnamon stick and a pinch of ground vanilla
Put everything in a bowl (not plastic or aluminum) and stir until the sugar is dissolved. Place cold for a day or two.
And just like the elder blossom lemonade: Filter the lemonade (can be done through a kitchen towel) pour it into bottles and store in the freezer. When you want to drink it just pour some in a glass or a jug and add water until the lemonade is perfect according to your taste!