A friend of mine likes bitter beers but shies away from strongly hopped beers because he's very sensitive to the cheesy or sweaty flavor that hops can give.

I've noticed this flavor in a few commercial beers, most recently Six Point's Brownstone Brown Ale which I normally love.

What compound is responsible for this flavor/aroma and what can one do about it.

ERRONEOUS [Sorry, I misspoke here based on something I heard on the basic brewing podcast.]

Since lambics and other beers that use debittered hops are specifically trying to attain that cheesy flavor and aroma, I assume that this is a characteristic of old hops.


Lambics use debittered hops for their antimicrobial properties. The cheesy flavor that old hops impart is a flaw, usually driven off via the boil.

  • I think you are using a poor source of hops if you suspect cheesy/sweaty flavors in amarillo. Secondly, come visit me and I'll give you an appropriate lambic because lambics don't have cheesy/sweaty flavors in them either. Denny's answer nails it.
    – brewchez
    Nov 11, 2011 at 0:58
  • 2
    I didn't say that this was a flaw in my beers. I buy leaf hops by the pound from hopsdirect.com, split into vacuum-sealed bags and store in a dark freezer until needed. I have aged aroma hops experimentally based on info in the Daniels book, but have never gotten this cheesy flavor. I've clarified the post, lest I damage my spotless reputation. I accept your offer of free lambic. :) Nov 11, 2011 at 16:02
  • Cheers man, cheers.
    – brewchez
    Nov 12, 2011 at 0:07

3 Answers 3


What accounts for it?

Okay, I guess research would've been a better approach here. Took me a couple of Google searches to find this page. The culprit is a compound called isovaleric acid.

Interesting info about it on Wikipedia: http://en.wikipedia.org/wiki/3-Methylbutanoic_acid

It is a product of aging and its attendant oxidation.

What to do about it?

  1. Use the freshest hops you can get.
  2. Boil longer. Isovaleric acid is apparently a volatile that will be driven off via the boil. You're less likely to have it in the final product if you boil the hops for longer.
  • Nice. Upping your game with this answer for sure. Upvoted and drinking some lambic in your honor.
    – brewchez
    Nov 12, 2011 at 0:08

It's a sign of oxidation in the hops. If they smell like that, don't use them. Lambics and other beers that use old hops aren't trying to achieve that character. The reason they use old hops is to remove any flavor or aroma characteristics from them, not to get the cheesiness.


The bittering comes from the acid resins in the hops. If it's a low acid hop, you're more likely to pick up on the other flavors in the hop.

  • True, and fresh hops don't smell cheesy.
    – brewchez
    Nov 11, 2011 at 0:58

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