This is how I use gelatin to clear beer. I'm sure there are other ways. I add it to already fermented beer after the beer has been chilled. You can add it to "warm" beer too, but might get different results. Summary: 1 tsp gelatin in 1 cup of cool water, let it bloom, heat in bursts (microwave) and stir until clear, then pour in.
Helles Brew Log Entry: