Clarifying Beer

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 215ºF for at least one hour. If the boil is not successful then fine flocs are created and remain suspended in the wort. Clarifying agents during the end of the boil can aid in the removal of particles and help to produce a clear beer.

Wort cooling causes the proteins to interact with polyphenols to precipitate as cold break. It is essential that the cold break be precipitated as much as possible, which is done by rapid wort cooling. The wort must be force-cooled to below 50ºF to secure a satisfactory break, and it precipitates best at 32 to 41ºF. A sparkling clear beer can be brewed by cooling the wort just above freezing until it becomes slushy. This procedure reduces the need for clarification. A long, slow cooling does not give a good cold break because more protein is trapped in suspension producing a finer trub, chill haze, and sometimes a sulfur-like aftertaste to the beer.

During fermentation several physical changes occur, which both produce particles, and facilitate their removal. First is yeast reproduction creating more yeast cells an a lower pH which facilitates the interaction of protein and polyphenols to form NMP's. As the alcohol level increases the viscosity of the brew is decreased which aids in the sedimentation of the particles. So the longer you can restrain yourself from tapping into or pouring yourself a cold one the clearer the beer will be. After fermentation further sedimentation occurs during the cooling of the beer prior to serving. Particle removal at this stage can be augmented by isenglass and auxillary clarifying agents.

The most popular clarifying agent is, no doubt, Irish Moss. Irish moss is a type of seaweed gathered along shores of the north Atlantic, including Ireland from whence it derived its name. It sometimes is referred to as carrageen, the name of its active ingredient. Irish Moss helps coagulate and reduce haze forming proteins. Recommended usage is 1 teaspoon per 5 gallons of beer (wort). Add 15 minutes before the end of the boil. Whirlfloc is Irish Moss prepared in a quick dissolving, highly soluble tablet form. It does the same thing as Irish Moss only that it comes in a tablet form. Usage is 1 tablet per 5 gallons.

Isinglass is a fish-derived additive that's primarily used to help speed up the clarification of cask-conditioned ales, although some beer-makers will use it to reclaim batches that didn't filter properly. When the beer is racked into a keg isinglass finings can be added along with priming sugar and dry hops before the keg is sealed up for conditioning. Isinglass contains a very pure form of collagen. Isinglass involves stabilizing the protein and when added to beer isinglass acts like a large open net with positive charges on the surface of the molecule. These charged sites act like little magnets and electrostatically bind yeast cells, due to the negative charge of yeast. The pH of beer is usually around 4.5 and at this level the collagen begins to precipitate from solution. As the collagen precipitates it falls through beer pulling yeast to the bottom of the fermenter. It is also important that you store and use your finings at a temperature range of 42–55 ºF (6–13 ºC), or they simply will not fine your beer correctly.

Gregory McLaw is a regular contributor to www.makebeerathome.info and enjoys brewing and drinking his own beer.

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