01 - Rinse cranberries thoroughly, removing any soft or discolored berries.
02 - Combine cranberries and water in a large saucepan. 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 solids to extract juice. Discard solids.
05 - Return the strained juice to the saucepan. Stir in sugar over low heat until dissolved, then adjust sweetness as desired.
06 - Incorporate lemon juice and orange zest if using, stirring to combine.
07 - Allow the juice to cool. Transfer to a clean pitcher or bottle and refrigerate until chilled. Serve over ice or as preferred.