Grapes cause a stable association with the North Caucasus. It is grown there, cared for and cherished, loved and knows how to cook.
Put the berries in a saucepan and heat over low heat until they burst and give juice. Remove from heat and strain. Extract the maximum juice with a pusher, return it to the pan. Remove the skins.
Add sugar and lemon with skin (pitted!), cut into medium wedges.
Increase heat to medium and cook, stirring constantly, until thickened. Divide into 2 banks. Seal, turn upside down until completely cool.