Bloom the gelatin: Pour 1/2 cup cold water into a bowl. Sprinkle the unflavored gelatin evenly over the surface. Let it sit for 5–10 minutes until the granules absorb water and turn spongy.

Heat the liquid: In a large measuring cup or saucepan, bring 2 cups of water to a boil. If using tea, brew it strong; if using lemon/lime juice, combine with water to make up the total hot volume.

Dissolve: Pour the boiling water over the bloomed gelatin. Stir slowly for 1–2 minutes until completely dissolved and clear—no grainy bits.

Flavor and sweeten: Add your chosen flavor base and sweetener. Start with less sweetener than you think you need, taste, then adjust. The mixture should taste slightly sweeter than you want the final dessert, because cold mutes sweetness.

Optional strain: If you used zest or tea leaves, strain through a fine mesh sieve for a smooth finish.

Chill: Pour into an 8x8-inch dish, individual cups, or silicone molds. Refrigerate until fully set, about 3–4 hours. For firmer cubes, chill overnight.

Serve: Cut into squares or unmold. Top with a dollop of sugar-free whipped cream, a few berries, or a sprinkle of zest if you like.