01 - In a medium saucepan, combine water, sugar, and grated ginger. Bring to a gentle boil, stirring to dissolve the sugar.
02 - Reduce heat and simmer for 5 minutes. Remove from heat and let the mixture steep for 10 minutes.
03 - Strain the mixture through a fine sieve into a large bowl, discarding solids.
04 - Stir in the lemon juice. Taste and adjust sweetness as needed.
05 - Cool to room temperature, then refrigerate for at least 30 minutes until thoroughly chilled.
06 - Pour into bowls or glasses over ice cubes if desired. Garnish with crystallized ginger, mint leaves, and lemon zest.