What is Cooling in Home Beer Brewing?
Beer clarity is essential for many beer styles, and can make or break a beer in a competition. There are many ways to help clarify your beer, and some are easier than others.
A semi-advanced home brewing technique used to improve clarity is a process called “cold crashing.” Just hearing the term may bring to your imagination a much different process than what is actually involved in cold crashing.
If done correctly, cold crashing will give your beer a clean, crisp appearance.
1. What is Cold Crashing?
Cold crashing is a process used to clarify home brewed beer by cooling it to near-freezing temperatures before bottling. Cooling the beer actually encourages yeast and other sediment suspended in the beer to flocculate (group together) and sink to the bottom.
This allows you to transfer the beer out of the fermentor for bottling while leaving behind much of the sediment that would cause a haze in the finished beer.
2. How is Cold Crashing Done?
To cold crash a beer you simply need to place it in a temperature-controlled environment. A lagering fridge that is outfitted with a temperature controller (this controller is most often recommended) is ideal. Regular refrigerators actually fluctuate in temperature which causes problems with the beer, while a fridge with a controller is held at a constant temperature.
The cold crashing temperature that is recommended varies from 33 degrees F to 40 degrees F, with 38 degrees F being the most common.
The recommended duration of cold crashing also varies. Some brewers say that only a day or two is needed, but it is most common to cold crash for one week.
3. Can Both Lagers and Ales Be Cold Crashed?
Although cold fermentation is only done for lagers, cold crashing can be done on both ales and lagers.