What is the primary use of Irish Moss in brewing?

The primary use of Irish Moss in brewing is as a clarifying agent during the boil. Irish Moss, which is a type of seaweed, contains a substance called carrageenan that helps to coagulate proteins and other particulate matter present in the wort. When added to the boiling wort, it promotes the formation of trub, which is a mix of solid particles that precipitate out during the boil. This process effectively helps to clear the beer by reducing haze and improving its visual appearance, leading to a cleaner, brighter final product.

While it may have other secondary effects, such as contributing minimal flavor or aroma depending on the amount used, its main function is focused on clarification. Thus, brewers often include Irish Moss in their brewing process to achieve a more polished final beer that is visually appealing to consumers.