Off Flavors when carbonating naturally

So far I've successfully brewed 3 five gallon batches, American IPA, Pale Ale, and a Mild brown ale. All of which I've carbonated naturally in bottles. Every batch has a distinct almost ethanol fruit off flavor that comes after I have bottled. I make it a habit to taste my beer at all stages of brewing from boil to finished product. This 'ethanol fruit' flavor only appears after I bottle. Im wondering if these are esters produced from the sugar I add to naturally carbonate in the bottles. The bottles carbonate at room temp. and are then moved to a fridge. I guess my question is, is tis flavor produced from the temperature the bottles carbonate at? Or the sugar itself thats added. Could this be fixed by force carbonating? or do I need to carbonate at a temp more like what I ferment at?

I suspect it's not from bottling, but I'm also having a hard time understanding the flavor you are describing. Maybe you could share your beer with an experienced brewer, at a homebrew club or homebrew store and ask for their opinion.

I bottle condition, usually around 70 F, with no off-flavors produced.

It is possible for off-flavors to show up in the bottle for various reasons. Some dissipate quickly, others slowly, and others are there to stay. Age the bottles for a while - it sounds like you have an acetaldehyde problem.

I've had English ales lose some fruity esters after bottle conditioning, but not produce them in the bottle. But like pappers said, without experiencing what you're describing, it's hard to say.

Carbonating actually tends to bring out more of the flavor and aroma that were already there. What temp are you fermenting at? The higher fermentation temp, the more fruity esters are produced

I agree with the previous posters.

You didn't mention how long you've let the beer bottle condition. Maybe it's still green? Time heals a lot of beer problems.

I also suspect that the flavors, assuming it's not green beer, may not be from the carbonation process. I'd look into what are my three top concerns with every beer:

- Sanitation
- Yeast pitch rate
- Fermentation temperature

Finally, I carbonate at 70-82F, which is what my house temp is usually at depending on the season. I don't notice any off flavors (and lately I've been doing nothing but light ales - Cat 6 BJCP - which tend to show mistakes more prominently).

Carbonation temps need to be in the 70-80F (IMO). Any lower and carbonation will just take way too long (if at all, depending on temp). Any higher and you may be ageing the beer too fast (again, IMO).

How long are you letting the beers condition before fridging them and deciding there's something wrong? All fermentations, including the carbonation process has the potential to produce byproducts of fermentation, the yeast is tossing off waste products as it goes along eating the sugar to ferment the beer or carb it. But when left alone, the yeast will usually go back and clean up those byproducts. That's why we talk about prolonging yeast contact and bottle conditioning.

The yeast are fastidious creatures and like to clean up any messes.

So I would try ignoring your beer for 2-3 weeks LONGER than you currently are- don't put them in the fridge where the cold puts the yeast to sleep and retards any conditioning process. Rather leave them warm longer, and see if the yeast will get rid of your offending flavor.

I've found a lot of beers need as much as 8 weeks (or more for higher grav) to come into their own.

So I would just pull out the beers you have in the fridge right now, give them a shake, and leave them for a few more weeks, just to see if the yeast will make them better. I've found beers that were 6 months or more in the back of closets, that were pretty mediocre initially or downright crappy, that have been vastly better, with some extra time.

True that Revvy! I found a couple bottles of a bitter I bottled last December. I'd thought the batch was mediocre at best back then, but last night I had one with dinner and it was pretty good. The off flavor I'd disliked (I think it was diacetyl from a hot ferment) was gone, as was any sign of the EKG I dry hopped with, but the beer was alot better!

All great advice. Just to add my own experience, on my first brew I wanted to taste the progression of flavor. When I opened a bottle at 1 week bottle conditioning, it had a very strong banana flavor. A week later, it was mostly gone. Another week later, it was completely gone, and it it's place was the nice citrus/coriander I wanted (Belgian White). Skip ahead another couple weeks, and the flavor has continued to mature, and it seems every bottle I open tastes better than the last.

For my second brew, I'm not touching a bottle until at least 3 weeks have passed.

I love this site already! Posted last night and already 9 responses. Its a brewers best friend!

After I bottle I allow the bottles to sit in my house for 2 weeks before I move them into the fridge. Come to think of it, Im possibly being a little over-zealous. I cracked a beer thats been sitting in the fridge for 2 months and still found that off flavor. So I'll take the advice and take a bottle into a local brew shop of mine and ask some opinions.

As for my fermentation temp. Thats completely controlled. I have a fermenting fridge with temp control so I really dont think this flavor is caused by that. I've experienced that problem before and the flavor was way different than it is now.

Fermentalist said:

After I bottle I allow the bottles to sit in my house for 2 weeks before I move them into the fridge.

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That's your issue in a nutshell...they're not even done carbing and conditioning yet when you put them in the fridge.

The 3 weeks at 70 degrees, that we recommend is the minimum time it takes for average gravity beers to carbonate and condition. Higher grav beers take longer.

Stouts and porters have taken me between 6 and 8 weeks to carb up..I have a 1.090 Belgian strong that took three months to carb up.

And just because a beer is carbed doesn't mean it still doesn't taste like a$$ and need more time for the off flavors to condition out. You have green beer.

Temp and gravity are the two factors that contribute to the time it takes to carb beer. But if a beer's not ready yet, or seems low carbed, and you added the right amount of sugar to it, then it's not stalled, it's just not time yet.

Everything you need to know about carbing and conditioning, can be found here Of Patience and Bottle Conditioning. With emphasis on the word, "patience."

Fermentalist said:

I love this site already! Posted last night and already 9 responses. Its a brewers best friend!

After I bottle I allow the bottles to sit in my house for 2 weeks before I move them into the fridge. Come to think of it, Im possibly being a little over-zealous. I cracked a beer thats been sitting in the fridge for 2 months and still found that off flavor. So I'll take the advice and take a bottle into a local brew shop of mine and ask some opinions.

As for my fermentation temp. Thats completely controlled. I have a fermenting fridge with temp control so I really dont think this flavor is caused by that. I've experienced that problem before and the flavor was way different than it is now.

Click to expand...

Beers will not age and mature in the fridge. Whatever it is going in to the fridge, is what it will stat even months later. Cold puts the yeast to sleep and they stop making the taste better. Take them out, let them warm up and the yeast will get back to it.

boy do i feel dumb. thanks for the advice! cheers!