When you are working with gelatin in a recipe, the directions will typically ask you to “bloom” the gelatin before using it. Blooming is the process of soaking gelatin in cold water before using it. The water serves to soften the gelatin, whether you are using gelatin sheets or powdered gelatin, and prepare it to dissolve easily when combined with the rest of your ingredients. If it isn’t bloomed, the gelatin can leave you with lumps in your recipe, or even with clumps of undissolved gelatin. After the gelatin has bloomed, you can melt it over a water bath or in the microwave before incorporating it with the rest of your ingredients.
To bloom powdered gelatin, simply place a small amount of cold water in a shallow bowl. Sprinkle the gelatin evenly over the top of the water. It will begin to absorb the water and swell in size. Let the mixture stand for 5 minutes before proceeding with the recipe. You will need about 1/4 cup of water per 1/4 oz of gelatin (one packet of powdered gelatin).
To bloom sheet/leaf gelatin, soak the sheets of gelatin in a bowl of cold water for 5 minutes. The exact amount of water does not matter, but a bowl with 1-2 cups of water is easy to work with. When the gelatin sheets have softened, gently squeeze to remove excess water, then proceed to melt the sheets as directed in your recipe, by melting them in the microwave or by stirring them in with other warm liquids.