Sanitize all equipment including the carboy, airlock, bung, funnel, strainer, and bottles using a food-grade sanitizer, then rinse thoroughly.

Rinse fresh blackberries or thaw frozen berries, inspect for debris, and gently place them into the sanitized carboy.

In a large pot, heat 1 gallon of water to 160°F to 170°F (71°C to 77°C), remove from heat, then slowly stir in 3 pounds of honey until fully dissolved (about 10 minutes).

Pour the warm honey water over the berries in the carboy and allow the mixture to cool to room temperature (65°F to 75°F / 18°C to 24°C), about 2 to 3 hours.

Once cooled, add 5 grams pectic enzyme and 5 grams acid blend, stir gently, and let rest undisturbed for 12 to 24 hours.

Rehydrate 5 grams of champagne yeast in 1/4 cup of room-temperature water for 15 minutes, then gently stir into the carboy.

Sprinkle 5 grams yeast nutrient on top, attach the airlock filled halfway with sanitizer solution or sterile water, and seal the carboy.

Store the carboy in a dark place at 65°F to 75°F (18°C to 24°C) and ferment for 4 weeks, checking daily that the airlock is bubbling.

After 6 to 8 weeks or when specific gravity is 0.990 to 1.010, siphon the mead off the sediment into a clean, sanitized secondary vessel, leaving solids behind.

Let the mead age in the secondary vessel for 2 to 4 weeks to clarify, then siphon into sanitized bottles, cap or cork them, and store upright or on their side.