In a recent series of online articles, we offered our homebrewer readers some tips for brewing clearer beer. One of the techniques we discussed was the use of kettle finings such as Irish moss and Whirlfloc to promote a strong cold break. But what exactly is cold break? And is it beneficial, bad, benign, or just beside the point?
Cold break is the catch-all name for all of the crud that precipitates out of solution when you rapidly cool wort after the boil. A good cold break looks like miso soup or egg drop soup, with lots of little flecks floating around within otherwise clear wort. Those little flecks consist of malt proteins, hops matter, and malt tannins (polyphenols).
The composition of the cold break depends, naturally, on the composition of the raw ingredients used to prepare the wort (well-modified malts and undermodified malts make for different cold breaks), but it also depends on your chosen mash schedule. If you’ve ever conducted a decoction mash, then you’ve no doubt been shocked at the amount of silt-like grit that remains in the grain bed after lautering. This gunk goes right into your wort in a single-temperature infusion mash, but the boil that takes place during decoction helps remove some of this stuff _a priori. _