How to make
Clean, wash and drain the blackberries.
Mash them in a deep container.
Put 12 1/2 cups (3 L) of water to boil in a pot with the citric acid, then pour it over the mashed blackberries.
Stir and strain the mixture through a fine sieve or strainer.
Add the sugar, stir again and leave it for 12 hours until the sugar melts completely.
Distribute the ready syrup into jars, close them and store in a cold area.
