Adult Agua Fresca

Supporting preparation and ingredient notes: Wash and scrub the whole watermelon under running water before cutting, and use clean equipment. Juice the watermelon. The simplest version is plain watermelon juice frozen as-is; it works without any other ingredient. For a brighter, more seasoned rock, add the juice of about 4 limes and fully dissolve 2 g salt per 1 L watermelon juice. The lime and salt are optional flavor boosters, not requirements; taste before freezing because lime size and acidity vary. Sea salt is preferred, but another food-grade salt may be used. Freeze solid in approximately 2-inch (5 cm) whiskey-ice molds, then transfer the rocks to an airtight freezer-safe container or bag. Keep continuously frozen at 0°F (-18°C) or below and use within 3 to 4 weeks for best quality. For hibiscus-infused tequila or rum, place 25 g (about 0.9 oz by weight) food-grade dried hibiscus flowers in a heat-safe container. Bloom with about 100 mL very hot or just-boiled water, equal to 3.4 US fl oz or about 6 3/4 US tablespoons. Remove the container completely from the heat. With no open flame, lit burner, hot element, spark, or other ignition source nearby, carefully add one full 750 mL bottle of the named spirit. The spirit will cool the small bloom; no separate room-temperature cooling step is required. Never pour or handle high-proof alcohol near an open flame or active heat source. Start the 4-to-6-hour infusion when the spirit is added. If convenient, gently invert or stir the infusion 2 to 3 times; this is optional. Strain thoroughly and transfer to a clean, labeled container. This recipe uses 1 oz of Cordial Craft per drink. That is more than the label's 0.75 fl oz serving, so a bottle makes fewer drinks at this measure.