I just brewed a jalapeno ipa and am stumped as to why the abv is so low.

The OG was 1.037. During the primary, the activity was very intense... like more bubbles than most other beers I've brewed. It kept up for about 5 days, then slowed, and I racked it after 10 days. When I took the next gravity reading it was only 1.028. I threw some corn sugar in there to hopefully kick off more fermentation. I just took another reading after waiting 5 more days and the gravity hasn't changed.

The temp has remained pretty steady at 68-72.

So, my real question is: Is it possible for the yeast to feed like crazy but produce no alcohol?

Here's the recipe:

  • 2lb 2-row
  • 7lb light malt
  • 2oz columbia hops 2oz citra hops
  • American ale II yeast
  • Jalapenos in boil and a few at end
  • If the yeast eats suger and produce corbone dioxide it will for sure procuce alcohol as well. Maybe the high gravity comes from something else than the suger. I have no experience from Jalapenos in beer, but maybe something from the Jalapenos dissolved and raised the gravity of the beer. You will probably be able to tell if the suger is still there when you taste it.
    – user613068
    Commented Sep 17, 2015 at 8:55
  • Are you confident in your OG? Have you tasted it to try and see if it tastes like there is alcohol?
    – Mr. Boy
    Commented Sep 17, 2015 at 11:21

2 Answers 2


There are two reasons I can think of:

  1. Capsaicin from jalapenos killed your yeast. If it can do that to yeast in baking, why not in beer? Required concentration would be high, but we don't know yours. Or maybe something else killed it?

  2. High gravity is not from fermentable sugars.

To test which one is the case, take a big amount of baking yeast, a cup or two of your beer, and see. If baking yeast can ferment it further, it means yeast in your tank are dead. If they just go down without changing gravity, the problem was with the mash, not fermentation. Solutions, respectively, are:

  1. Add a big amount of fresh yeast slurry in hope it will ferment your beer before it dies.

  2. Nothing to do, just bottle it and leave it to age. It might actually be good in few months, with malty sweetness countering jalapenos.


How did you add the jelapeno? It might be that the plant matter is causing the extra dissolved items in the beer.

I had a maroela beer that was at 1.015 when I added the maroelas. The beer ended up at 1.028 just because of the plant material.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.