Put cranberries and water in a large saucepan over medium high heat. Bring to a boil. Then reduce heat to low. Simmer cranberry mixture for 20 minutes, stirring often to prevent sticking. Pour mixture through a fine sieve set over a second saucepan, pressing very firmly on solids to release as much juice as possible (I also scrape the outside of the sieve with another clean spatula to help release the juice).Stir sugar into strained cranberry mixture and cook over medium low heat for 2 minutes or until all the sugar is dissolved. Pour cranberry mixture into desired mold(s) and chill until firm.