Sweet of Blackberry (Blackberry Preserve)

"Sweet" is a specialty of fruit that is, in some Balkan countries is used for serving guests and also as an ingredient in various types of cakes. Sweet can be made ​​from blackberries, strawberries, raspberries, plums, cherries, quince, melon ... There are many easy recipes for making sweet. Here's one:

Ingredients:

2.3 pounds of blackberries,
2.9 pounds of sugar.

Preparation:

Blackberries wash with water several times.
Placed in the pot row of blackberry then row of sugar and so on until all the berries are consumed.
The last row should be sugar.
Cover the pot with towel and leave to rest for 24 hours.
Cook over high heat until the juice becomes thick.
Removed foam from the surface.
When cool pour into jars and cover with plastic wrap.