01 - Rinse cranberries thoroughly, discarding any that are soft or discolored.
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 the mixture through a fine-mesh strainer or cheesecloth into a large bowl, pressing to extract as much juice as possible. Discard solids.
05 - Return juice to saucepan; stir in sugar over low heat until fully dissolved. Adjust sweetness to taste.
06 - Incorporate lemon juice and orange zest if desired, stirring to combine.
07 - Allow juice to cool, then transfer to a clean pitcher or bottle. Refrigerate until chilled and serve over ice or as preferred.