Put 13 cups of fresh black currant leafs in a big bowl (or small bucket) add 2 tbsp citric acid 4 lbs sugar and 12 cups of boiling water 3 sliced lemons (if you want some color also add 2-4 cups of black currants).
Stir well so the sugar is dissolved and let it rest in a cool place (make sure the lemons are covered) for three days.
Pour it into bottles or small plastic bags and store in the freezer. When you want to drink it just take one out and let it melt then dilute it with water. Some like just a hint others want their lemonade stronger 😀