You an use any berry that you like the most
2 cup of blackberry
2 liters of water
About 3 table spoons of potato starch
About 2 cups of sugar or to taste
Let’s take 2 cups of berries and press them through the metal sieve. Set the juice a side and add the left over pulp to the pot and add 2 litters of water. Bring to boil and let simmer for about 10 minutes.
Strain the liquid and discard the berry leftovers. Set about 1 cup of liquid aside and put the rest back in the pot and bring to boil. Then lower the heat. Add sugar and mix. Take the cup of liquid that was set a side once it cooled down and mix with potato starch. Make sure that the mix is smooth and there are no lumps of starch.
Add the juice that was reserved and the starch mix. Let simmer for a minute or too for the liquid to thicken.