I kegged a black porter, from an extract kit 4 days ago, it is still carbonating.

It has a green apple taste to it.

I let it sit in the primary for 7 weeks, a midwest supplies 6.5 gal bucket w/ a lid that does not have a gasket.

I transferred to a big mouth bubbler for 7 days and then kegged.

I recently brewed another beer, using the same bucket and lid and you can tell there is pressure in the bucket, as the lid is pushed up toward the middle of the lid, when I push down on the lid gently, bubbles come thru the airlock. The airlock is not very active, I think air is escaping since the lid is not air tight. I consulted an employee at midwest before buying the bucket and lid and they assured me it is fine and I have read on here about other people having similar concerns about lids w/o a gasket.

I have had other beers that had a green taste to it and after a couple weeks in the keg it mellows down.

I am looking for some insight as to what may of gone wrong, did I keep it in the primary too long? That is my first thought. I'll definitely only have it in the primary bucket for no more than 2 weeks going forward, as I use my big mouth bubbler for secondary.

Also, it brewed at a decent temperature and I sanitized all the equipment, reading up on green tasting beer leads me to believe it had to do with too air exposure.

I also used us-05 dry yeast and it took about 30 hours for the bucket lid to show that it had built up pressure in the bucket.

  • If by green apple taste you mean like a jolly rancher then it's oxidized.
    – Escoce
    Dec 2, 2015 at 20:42
  • Not that green apple, but it tastes like it still needs conditioning/mellowing time.
    – Brad
    Dec 3, 2015 at 0:28
  • @Brad did you ever get to the bottom of this? I've having this same problem on a lot of my beers... Dec 30, 2019 at 21:17

1 Answer 1


Generally green apple (acetaldehyde) is due to fermentation not being complete.

Did you cold crash? Did you verify that your beer was done fermenting?

It is strange that your fermenter builds up so much pressure, even with an airlock attached. Are you filling the airlock to the top or to the line?

Too much CO2 will cause the yeast to slow down, which might be why it did not ferment out (if that is the problem).

Here is more info on Acetaldehyde

http://howtobrew.com/book/section-4/is-my-beer-ruined/common-off-flavors http://www.aroxa.com/beer/beer-flavour-standard/acetaldehyde/

  • I had it in the primary bucket for close to 8 weeks, it was a 6 week extract kit, then transferred to secondary for a week then kegged. I had the airlock filled with star san up to the line it recommends filling it up to. I never do gravity readings. On brew day I used a wort chiller and put in whirloc tablet 15 minutes before the end of boil.
    – Brad
    Dec 4, 2015 at 17:24

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.