What is this off-flavor?

[grathan]

You brew up a light colored beer with no flavor or finishing hops perhaps 15-25 IBU total. It pours into the glass with very little head, in fact you can see much of the beer's surface without any foam. You breathe in and take up a nasty funk that smells like a combination of onions, wet dog, and perhaps that smell on the asphalt of earthworms after a rainstorm.

I say off-flavor, but I guess it's only aroma because you can't taste it for the most part.

 

[duboman]

You brew up a light colored beer with no flavor or finishing hops perhaps 15-25 IBU total. It pours into the glass with very little head, in fact you can see much of the beer's surface without any foam. You breathe in and take up a nasty funk that smells like a combination of onions, wet dog, and perhaps that smell on the asphalt of earthworms after a rainstorm.

I say off-flavor, but I guess it's only aroma because you can't taste it for the most part.

Perhaps you can review this http://www.beerjudgeschool.com/uploads/Beer_Characteristics_Flash_Cards.pdf and pinpoint a more descriptive off flavor, causes and cures, if any

 

[unionrdr]

Maybe like musty wet cardboard?

 

[grathan]

Musty wet carboard may describe it, but remember.. we're only talking aroma here.


For the record, we're talking Wyeast Kolsch yeast. I have had this smell in commercial beers before, but no idea what yeast they've used.

 

[unionrdr]

It comes out as a smell & a nasty flavor. It's usually caused by oxidation.

 

[jonmohno]

Do some bottle conditoning or lagering and see what happens. Im suspecting DMS also.

 

[unionrdr]

If it is indeed oxidation,it'll only get worse with time. If it's something else,condition them for a while & see if it clears up.

 

[grathan]

Perhaps you can review this http://www.beerjudgeschool.com/uploads/Beer_Characteristics_Flash_Cards.pdf and pinpoint a more descriptive off flavor, causes and cures, if any

Thanks, there is just too many possibilities here though. Let me try go give some more details on the batch I made.

mash was on the acidic side of things
plenty of 02 for yeast
Ro water 22 TDS assumed mostly bicarbonate
grain was mostly Best Malz pilsner with 0.5 vienna
1.5 oz (60 min) Mittelfrueh hops

ferment 2 weeks on very low temps for wyeast Kolsch yeast, beer is almost 2 months old( mostly 37*F outside of ferment )

Keg was cO2 purged.

 

[duboman]

Did you lager this and did you do a D-rest? Lots of pilsner and not enough lager time screams DMS as a possibility. But that would be buttered popcorn 2 weeks is not a long enough time to lager.

 

[chickypad]

Did you lager this and did you do a D-rest? Lots of pilsner and not enough lager time screams DMS as a possibility. But that would be buttered popcorn 2 weeks is not a long enough time to lager.

I think we might be confusing DMS and diacetyl. DMS is cooked corn/vegetable - maybe from only a 60 min boil with pilsner malt, or slow cooling, or boiling with the lid on. Diacetyl is more buttery popcorn, produced by some yeasts especially lagers if no diacetyl rest done.

 

[Randy_Bugger]

I know what smells you are talking about. The wet dog or wet dirt after a heavy rain is something I have smelled in a few commercial beers. Most recently, I smelled it in a Duvel and normally it isn't there. I have also smelled it in some wild ales and Saisons. I've never smelled it in one of my home brews. Knocks wood.

The smell is gross and very un-appetising. I have no idea where it comes from. The off odor / flavor charts don't mention it.

My best guess is an infection of some sort. I think it's safe to say Duvel has their brewing process and recipe dialed in by now, but even they are not immune to an occasional infection.

 

[duboman]

I think we might be confusing DMS and diacetyl. DMS is cooked corn/vegetable - maybe from only a 60 min boil with pilsner malt, or slow cooling, or boiling with the lid on. Diacetyl is more buttery popcorn, produced by some yeasts especially lagers if no diacetyl rest done.

Totally correct it's been a long day.....my bad...oops

 

[chickypad]

Totally correct it's been a long day.....my bad...oops

time for a homebrew!

 

[duboman]

time for a homebrew!

I've had several, perhaps that's the issue

 

[unionrdr]

I've got a couple off flavor links you could try looking at; http://draftmag.com/offflavors/
http://morebeer.com/public/pdf/off_flavor.pdf