Brad from Beersmith puts out an excellent little newsletter. In the latest one, he talks about chilling your wort.
Here are two of the benefits of rapid chilling he quotes:
Improved clarity When you rapidly cool hot wort, many of the heavy proteins and tannins will no longer be soluble and will fall out of the wort. Siphoning the wort off of this cold break will result in a improved clarity and improve taste as well.
Reduction of volatile compounds Dimethyl Sulfide (DMS) which gives beer a strong sweet corn flavor can continue to break down after boiling and may be carried forward into the finished beer unless you rapidly cool the beer (Ref: Brewers Handbook by Goldhammer).
Now my experience with no chill suggests the first one is definitely a myth that continues to be promulgated. The separation of cold break in the cube is superb.
I'm less sure about the second - don't know enough. I've never had a DMS problem, assuming that my boil has been rigorous enough to remove it. "If the wort is cooled slowly these compounds will not be removed from the wort and will dissolve back in." (Palmer)
Because DMS is created at temperatures below boiling, cooling the wort too slowly means that excessive levels of DMS can be created which cannot be evaporated once the boil has stopped (homebrewing wiki) .
I'm not sure that makes sense to me. If the compounds are still in there, how does rapid cooling make any difference? The precursors continue to react until the temperature drops? If that was true, surely all the no-chill beers would struggle, particularly pilsners.
Anyone comment?
