Blooming involves mixing an ingredient with a liquid (water or fat), to enhance / activate the flavor, or saturate for easy dissolving. Can be cold or hot liquid. For cocoa powder – Blooming with hot water will intensify the flavor of cocoa powder by releasing the flavor molecules. For spices – Blooming in hot water or oil, will bring out the spice flavor compounds. For gelatin – Blooming in cold water, will saturate the gelatin, making it easier for the gelatin to dissolve evenly, and faster in hot liquids.