Irish moss is a fancy name for a red seaweed called carrageen which can clump together proteins from the hot break. These proteins, if left in solution, can cause beer to be hazy and cause staling. Irish moss helps these to settle out of solution when added at the last 20 minutes of the boil. An excellent clarifying agent that helps brewers achieve crystal-clear beers.
Usage Amount: 1 tsp. per 5 gallons