I have been cooling my wort after all the boiling by simply taking it off the heat and waiting two to three hours.

I have now seen a few places where they use an ice bath to cool the wort much faster. What would the difference in the end product be when you comparing post rolling boil wort cooled with an ice bath to those simply left at room temperature to cool down?

The wort is sealed from outside air with a spigot and a improvised air lock.

  • @MD-Tech - Not necessarily; basic homebrewing questions are considered on-topic here, especially for beginners who might be intimidated by the expertise at Homebrew. However, yes, Neil, you'll probably find much better answers, if not your answer already, at Homebrew. Nov 5, 2015 at 17:31
  • That said, might be an obvious question but, are you sure these places weren't using wort chillers? Nov 5, 2015 at 17:32

1 Answer 1


The technique you describe is called "No-chill" (see question 9699 and 5374) and is used by lots of homebrewers. Usually the hot wort is placed in a sealed food grade jerry can and allowed to cool overnight. Since the container is sealed and the boiling wort has heat sanitized the inside, the wort should store for months without spoiling and thus beer can be fermented whenever you get around to it.

Beware of using the air lock during cooling as the water in the air lock will probably get sucked back into the wort as it cools.

The main difference between a slow and fast cool is the hop utilization. The aroma hops (last 10 mins of boil) will stay in a hot solution longer during no chill and probably be utilized more like flavor hops (20-45 mins) so the final product may have less hop nose. Rapid chilling ensures that the last hop addition will contribute to the hoppy aroma.

There are many more no chill questions and answers on homebrew.stackexchange.com

  • Never had issues with the airlock.
    – Robert
    Nov 6, 2015 at 20:29
  • What about DMS? It is formed over 40 C, and evaporates only over 90 C, so fast cool is essential to get rid of it. Especially when using Pilsener malt or unmalted grains.
    – Mołot
    Nov 6, 2015 at 22:20
  • @Mołot - Long boils drive off DMS, which is why all pilsner recipes call for at least a 90 min. boil. The cooling process does not affect the total amount of s-methylmethionine (precursor to DMS) in the wort. (picobrewery.com/askarchive/dms.htm)
    – Rube
    Nov 6, 2015 at 22:41
  • @Rube Cooling won't affect precursor amount, of course, but precursor is pretty much tasteless and it's converted compound that matters. Many homebrewers don't bother with 90 or longer boil when using pilsner malt, and can get away with it by cooling fast.
    – Mołot
    Nov 7, 2015 at 11:05

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