I find it works better if you put the heated gelatin (regular unflavored Knox) into cold beer.
As stated above, I boil 1 cup of water, let it cool to ~ 100 degrees. Then you sprinkle it on top without mixing and let it stand for 10 minutes. Most of it will fall to the bottom. Heat it in the microwave for 30-45 seconds. Stop at 30 and see if you can get it to run fairly clear using a sanitized spoon to stir. If not, heat it for 5-8 seconds more and try again. As soon as its clear, its ready to add to cold beer. Do not boil the gelatin.
Give it 4-7 days contact with chilled beer and you will be amazed. I swear it seems to reduce some hop aroma, so be semi-wary with dry hopped brews.
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