What is Chill Haze?
How Do I get rid of Chill Haze?
Easily put, chill haze is the result of haze-producing proteins that reside in the beer. They do not react unless chilled, at which point they clump together. At that point, they become visible enough to reflect light. Since the particulates are white in color, they give the appearance of haze. These proteins are slightly heavier than the beer, so given enough time in the fridge (potentially weeks), or in cold temperature, they will fall out of suspension.
The use of fining agents in the boil kettle as well as before bottling/kegging can help to reduce chill-haze, as can a good rolling boil and a quick chilling to pitching temperatures after the boil is complete (forming your hot break). As far as fining agents, in the boil kettle, one of the more popular to use is Irish Moss.
After fermentation has completed, there are two other popular fining agents, if used, they both should be applied after the beer has been chilled in the fermentation vessel to help drop out the yeast as well as form the chill-haze. Two popular fining agents for this are gelatin, which can be added right before bottling or kegging (note: gelatin is not vegan friendly), or polyclar, which should be added days before racking off for bottling or kegging to allow it to settle out to the bottom of the fermeter. Polyclar is essentially powdered plastic and no one wants to drink plastic.
The process behind using Gelatin and Polyclar is as follows (thanks to Bertus Brewery):
With your beer chilled down and gelatin in hand, let's get to the process of fining your beer
- Get a microwave-safe glass cup. I like to use a pyrex measuring cup. Measure out 2/3 cup cold water. Any water will work, but I wouldn't use tap water if it tastes like crap.
- Add one teaspoon of gelatin, and stir the solution. I like to use using my thermometer probe, so I can check the temperature at the same time.
- Place the water/gelatin mixture in the microwave, and begin to heat it 15-30 seconds at a time, stopping to stir the solution and check the temperature. As it heats up, you'll notice the gelatin will begin to dissolve.
- The goal is to heat the gelatin to 150F, but not much over. If it climbs to 155 or so, that's fine, but I'd be hesitant to go much over 170F. We're not trying to make jello, rather just trying to pasteurize the solution.
- Give the mixture one last stir, and dump it straight into your beer. Gently swirl the fermenter or keg, and return it to your fridge or kegerator for 24-48 hours.
- If you used a keg, purge the headspace with CO2 to remove any oxygen that got mixed in.
Heres a BYO article on chill haze that's worth a read as well.