Beer Fact Friday: Irish Moss
Malt, water, hops and yeast might be the ingredients that give beer its color, texture and flavor, but there are plenty of other additives brewers can utilize to make their beers better. This beautiful stuff is called Irish Moss, a type of edible red seaweed that grows along the rocky Atlantic coasts of Europe and North America, and has been used by brewers as a “finings agent” for the past 200 years.
A majority of the plant’s body is made up of long, flexible molecules called carrageenan. In beer, this stuff carries a negative electrostatic charge, which makes it useful for removing haze-forming proteins, which carry a positive charge. When added to beer in powdered form—usually close to the end of the boil—Irish Moss gathers those oppositely charged proteins into large clumps, making them easier to remove from the wort and making the resulting beer cleaner and brighter.