4cupsfresh or thawed unsweetened frozen blackberriesplus extra for serving
1cupturbinado sugar, natural cane sugar, or grated palm sugar
1kaffir lime leafcrushed, or 1 tablespoon grated lime zest
1green cardamom podlightly crushed
0.5cupfresh Key lime juicetypically about 8-12 limes
1cupwaterfor simple syrup
2cupsginger ale or sparkling waterfor serving
Lime slicesfor garnish
Instructions
Press the blackberries through a fine-mesh sieve or squeeze through cheesecloth to extract about 1 cup of juice. Discard the seeds and place the juice in the refrigerator.
In a small saucepan, combine 1 cup of water, 1 cup of turbinado sugar, the kaffir lime leaf, and the cardamom pod. Bring to a simmer over medium heat and cook for 10 minutes to infuse. Remove from heat, strain out the solids, and let the syrup cool completely in the refrigerator.
In a pitcher, mix the fresh blackberry juice, the chilled infused syrup, and the key lime juice together.
Just before serving, stir in 2 cups of ginger ale (or sparkling water) and serve over ice, garnished with fresh blackberries and lime slices.