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Question: :My beer always seems to be cloudy. What can I do about it?

Answer: Unless you're brewing a Hefeweizen or Stout, nothing impresses your brew buddies like pouring them a sparkling clear beer. It also impresses beer judges more than the one point allocated on the judging form would otherwise indicate. Avoiding cloudiness takes a bit of work, but it's worth it.
Cloudiness can be the result of several different causes. So the first thing you need to do is figure out what the source is. Once you have that pinned down, different approaches are available. Some can be fixed with improvements in brewing technique. I'll discuss some of the causes and technique-based fixes first. Then I'll cover some of the fining agents that are commercially available.
The most obvious cause of cloudiness is unsettled yeast. If that bottle of beer starts out clear and get gets cloudy as you pour, you've probably got yeast. If you're serving from a keg, yeast typically blasts out with the first few glasses. However, it tends to be more persistent if you've had to move your keg just before the party.
There are two methods of reducing yeast cloudiness. The easiest is to reduce the amount in you beer containers. Give it enough time in secondary fermentation to settle out. If you're kegging, go with forced carbonation, since priming sugar causes yeast cells to multiply. The second approach is to repitch the beer with a highly flocculent yeast. Wyeast 1099 Whitbread Ale yeast would be a good choice.
If your beer is clear at room temperature but then gets cloudy in the fridge, you've got chill haze. Chill haze is formed from proteins and polyphenols. These are soluble in beer at room temperature and hence are clear. But at low temperatures, they combine to form fine insoluble particles.
The first attack against chill haze is to use a protein rest when you mash. See the Brewmaster article in the November 2000 Gazette for more details. If you're making an extract batch, try throwing in a half-pound of pale malt with your crystal steepings. Another thing to try is to lager the beer and then rack. Given enough time, the haze will settle out. The beer has to remain cold the entire time, though. Even a brief warming can cause the haze to redissolve, leaving you back where you started.
A third form of cloudiness is caused by starches. Starches most often result from poor mashing or sparging technique. Watch your mash temperature, and avoid disturbing the grain bed during sparging. If your brew setup has a false bottom, you might try switching to an EZ-Masher.
If you find that technique improvements alone don't get your beer as brilliant as you would like, then try some fining agents. I'll cover some that are available at the shop. For a more comprehensive information on beer clarification, check out the link at:
One of the most popular and simple-to-use fining agents is Irish moss. Irish moss is a type of seaweed. It works by combining with the polyphenols and protein in the wort. This makes it especially effective on chill haze. Irish moss is used in the boil. To use Irish moss, measure out about ½ a teaspoon per five-gallon batch and mix it into a cup of water. Let it soak for about half an hour. Then throw it into the boil about 20 minutes before the end of the boil. The moss and associated proteins will drop out with the hops and the cold break
Other types of fining agents are used in secondary fermentation or during bottling. Among these are Polyclar, Bentonite and Sparkolloid. Sparkolloid is particularly effective on yeast, whereas Bentonite and Polyclar are better for chill haze. Polyclar is actually claimed to be able to remove phenolic off-flavors from beer.
Of these three agents, Polyclar is the easiest to use. Add two tablespoons to a cup of sterile water and stir into a slurry. Then dump it into your secondary fermenter. For best results, keep the material gently agitated for an hour or so. Give it a few days to settle and then rack into bottles or kegs.
Bentonite and Sparkolloid are a bit more difficult to use, since they have be brought up to a boil with plenty of stirring before you use them. Then you need to stir them into the secondary just like Polyclar. See the above web link for complete details.
Any of these three finings can be used directly in bottles or kegs. However, you'll still have to avoid stirring it up later.
One final warning: Don't put in too much fining agents. You could end up pulling out too much protein. That will leave you with a thin-tasting beer and a weak head.