Clarifying Beer

Article by Gregory McLaw

It’s been nearly a month and you’ve waited patiently for your latest batch of homebrewed beer. The time has come and you open a bottle or pull the tap and begin to fill a glass of what you hope will be your next favorite beer (generally speaking my favorite beer is usually the one I’m drinking at the moment). The taste is great but the beer is hazy and not very clear. You know it taste good but it’s hard to convince your friends, who are used to buying and drinking sparkling clear beer, that the cloudy haze is alright to drink and really doesn’t affect the taste. It’s widely acknowledged that visual appeal is a major factor for most people when drinking a beer. So, how do we clear things up? A variety of clarifying agents (called finings) and techniques are available to encourage your beer to clear. The term “fining” can refer both to the process of clarifying beer or to the agents themselves.

Aside from infection and the introduction of foreign particulates into open vessels, beer clarity, or the lack thereof, is caused by yeast cells and non-microbiological particles (NMP’s). Sometimes the yeast is just stubborn and will not settle out of the beer. Different yeast strains exhibit different characteristics during flocculation which produce different problems in settlement. But the biggest problems with clarity, since they are more difficult to remove than yeast, are non-microbiological particles. The term NMP covers protein, usually associated with polyphenols and other molecules such as lipids, carbohydrates, and/or metal ions. NMP’s are produced, and should be removed, during each stage in the brewing process.

If you are an all-grain brewer then the clarity of your beer is affected by the amount of fine dusty starch and husk particles created during milling. Most of these particles can be removed during sparging and recirculating the wort through the mash bed prior to run-off. Coagulation of protein occurs during the wort boil. A successful boil means a more efficient coagulation of proteins resulting in large flocs which can be more easily removed as well as the removal of polyphenolic material which reduces chill-haze. A successful boil is one that begins with a high wort pH with sufficient proteins present. The boil should be around 215