01 - Rinse cranberries thoroughly, discarding any soft or discolored berries.
02 - Combine cranberries and water in a large saucepan and bring to a boil over medium-high heat.
03 - Reduce heat and simmer for 15 minutes, stirring occasionally until cranberries burst and soften.
04 - Remove from heat and strain mixture through a fine-mesh strainer or cheesecloth into a large bowl, pressing solids to extract juice. Discard solids.
05 - Return juice to saucepan, add sugar, and stir over low heat until fully dissolved. Adjust sweetness if desired.
06 - Stir in lemon juice and orange zest if using.
07 - Allow juice to cool before transferring to a clean pitcher or bottle. Refrigerate until chilled and serve over ice or as preferred.