Crush berries and press through a fine sieve. Pour into a large pan. Add sugar slowly and bring to a boil over high heat. boil 2 minutes. Remove from heat. Let stand 5 minutes, return to heat and slowly return to boil. Boil 3 minutes. Skim any foam from top. Pour into a sterilized quart jar. Stor in a cool, dark place with securely sealed lid.