Beer Clarity – What to Do About Hazy Beer
Beer clarity has become an important aspect of most beers since the first pilseners arrived. American light lagers are some of the clearest beers in the world with their low proteins and high adjuncts. Beer drinkers have come to expect their beer to be clear. So how does this affect the homebrewer? Commercial breweries use filtration to get those crystal-clear beers. For you, the homebrewer, there are quite a few things you can do to improve the clarity of your beers.
Chill haze is The number one cause in homebrew. Where does this haze come from? It comes primarily from the malt you use. The malt contains proteins, and its husks contain tannins (polyphenols). These proteins and tannins (along with other polyphenols) cross-link to form small complex chains which are too small to settle out. These protein-polyphenol complexes are soluble at warmer temperatures but will become insoluble at colder temperatures and form the haze you see in your homebrewed beer. These small protein-polyphenol chains can combine with oxygen to form larger chains that can settle out, reducing chill haze. But the clear beer comes at a price, oxidation, and staling. There are some things the homebrewer can do to reduce chill haze. Reducing chill haze caused by protein-polyphenol linking is a matter of reducing the proteins or the polyphenols (aka Tannins) or both.
Ways to Improve Beer Clarity and Eliminate Chill Haze
To reduce your beer’s protein and polyphenol levels, reduce some of the malt used in the recipe.
Try adding some adjuncts like corn, rice, or refined sugar such as the American lagers, Belgian-style tripels, or strong ales have.
Using a huskless malt like wheat or rye will reduce the polyphenols but increase the protein levels at low percentages in your grain bill. As the level reaches 40%, the amount of polyphenols is reduced to such a low percentage that the proteins have nothing to link with, and the beers are very clear.
Hops also produce polyphenols in your beer. Using lower alpha acid hops as your bittering hops will incorporate much more hop cone material into your wort, and thus, more polyphenols are extracted. Using high alpha acid hops for bittering will reduce the hop-derived haze in your beer.
Try adding a protein rest which will reduce the large proteins into small and medium-sized ones.
Achieve a good hot break by boiling the wort vigorously and then get a good cold break using a wort chiller (possibly even a pre-chiller). A large percentage of malt polyphenols survive the boil and chill, whereas a relatively small percentage of hop-derived polyphenols will.
Switch to a low protein or low polyphenol malt in your recipe.
Use a fining agent in your boil. Adding bentonite to the boil in the last 15 minutes will significantly reduce the protein and polyphenol levels. Try adding 10-40 grams per 5-gallon batch, but remember that bentonite absorbs a lot of water, too, so you may want to go with the lower end of the recommendation.
Adding fining agents after the boil to reduce protein levels is a common practice commercially.
Try using a batch sparge, which is known to reduce the amount of tannins extracted from the husks.
Filter your beer. Use a larger filter first, then switch to a small filter for polishing.
Make sure you lager at near-freezing temperatures (32°F or 0°C).
Minimize aeration during bottling and kegging. Increased dissolved oxygen in your bottle can promote a permanent chill haze.
Other Reasons For Hazy Beer
Check to ensure the beer clarity issue isn’t caused by wild yeast or bacterial infection. In this case, haze is an indication of a serious problem. Common bacterial infections in beer include Pediococcus diagnosis, which generates a lot of diacetyl. Lactobacillus bacteria can produce many flavors in your beer, some pleasant and some not-so-pleasant. A third type of bacterial infection comes from the coliforms. These types of bacteria produce vegetal flavors in your beer. You will most likely notice these hazes in the bottle after fermentation. The haze in the bottle indicates that you may have an infection. The solution to bacterial infections is better sanitation.
Another source of beer clarity problems is yeast. The yeast haze can come from wild yeast, a cultured yeast that may have mutated and can’t flocculate out of suspension, or a cultured yeast noted for its poor flocculation properties. If it is from wild yeast, look at your sanitation procedures. The wild yeast may have been transferred from repitching the yeast from another fermentation. Regardless of how it got there, it’s obvious that you shouldn’t reuse this yeast. You will find that some yeast cultures are just poor flocculation and recommend fining or filtration to get a clear beer.
You may be experiencing a chemical haze caused by an in-balance of chemicals in your water. A deficiency of calcium in your boil can cause a clarity problem from a chemical haze called oxalate haze. Make sure you have more than 25 ppm calcium (50 ppm is better) by getting a chemical water analysis. The calcium level may drop considerably when treating your water to lower bicarbonates. Add more calcium back as necessary. Minerals such as iron and copper at levels exceeding one ppm and tin exceeding 0.1 ppm can also cause a chemical haze. Try carbon filtering your water or diluting it with distilled water, RO (reverse osmosis) water, or bottled spring water to reduce these minerals below the haze-forming threshold.
Some brewers believe skimming the dirty head formed during fermentation will produce better beer clarity. Using a blow-off tube produces similar results when fermenting in a glass carboy. Another procedure is “dropping,” whereby the beer is siphoned out from under the krausen, leaving it and the trub behind.