The dreaded wet cardboard taste

Get advice on making beer from raw ingredients (malt, hops, water and yeast)
BrewHouse

The dreaded wet cardboard taste

Post by BrewHouse » Mon Jan 16, 2017 9:34 am

I have just kegged a batch of Yorkshire Bitter and have an overpowering taste of wet cardboard. I have never had this before but know it means that the beer is oxidised.

It spent 2 weeks in the FV completely untouched. I then siphoned it straight into the Corny making sure that the tube was at the bottom to minimise splashing. So far so good. The corny was filled right up to the max so I am guessing that there was 1-2 inches of airspace. I attached the gas and force carbed at 25psi by rocking the keg on its side for 2-3 mins.

First taste was overpowering wet cardboard. What I did NOT do was purge the airspace before force carbing. Is it possible that this tiny amount of air in the keg could have such a devastating an immediate effect on the beer? If not, I honestly can't imagine what has happened.

User avatar
vacant
Even further under the Table
Posts: 2167
Joined: Mon Aug 20, 2007 5:39 pm

Re: The dreaded wet cardboard taste

Post by vacant » Mon Jan 16, 2017 9:52 am

I don't think oxygen introduced from forgetting to purge will have had enough time to oxidise the beer and produce off-flavours as the reaction is slow.
I brew therefore I ... I .... forget

User avatar
Jocky
Even further under the Table
Posts: 2738
Joined: Sat Nov 12, 2011 6:50 pm
Location: Epsom, Surrey, UK

Re: The dreaded wet cardboard taste

Post by Jocky » Mon Jan 16, 2017 11:27 am

What is your fermenter? A bucket? Was the lid on tight after fermentation was done?
Ingredients: Water, Barley, Hops, Yeast, Seaweed, Blood, Sweat, The swim bladder of a sturgeon, My enemies tears, Scenes of mild peril, An otter's handbag and Riboflavin.

Matt in Birdham
Drunk as a Skunk
Posts: 764
Joined: Thu Oct 08, 2015 10:27 pm

Re: The dreaded wet cardboard taste

Post by Matt in Birdham » Mon Jan 16, 2017 11:41 am

Did you taste any of it before it went into the keg? It would be interesting to know when the oxidisation occurred. Did you dry hop?

User avatar
Kev888
So far gone I'm on the way back again!
Posts: 7701
Joined: Fri Mar 19, 2010 6:22 pm
Location: Derbyshire, UK

Re: The dreaded wet cardboard taste

Post by Kev888 » Mon Jan 16, 2017 12:18 pm

It seems deeply unlikely to me that lack of purging would give such an overpowering oxidised flavour; you minimised splashing and filled the keg mostly to the top. At one time (before obtaining gas) this was normal for me, and it still is for many. There may perhaps be a tiny increase in oxidation, but not to those huge levels.

Purging by just squirting CO2 in may only be partially effective in any case, since CO2 does not actually displace oxygen (they can share the same space). Its mainly the through-draft that helps carry some oxygen out.

So I'd be looking for another culprit. TBH I too am struggling to imagine what would give quite such a pronounced result, though. Two weeks in the fermenter is not excessive even were the lid not fully air-tight. The kegging wasn't notably poor. You didn't filter, so there will be plenty of live yeast. I don't suppose the keg could have an imperfect seal, at all? Or was there an unusual amount of aeration whilst the wort was hot?
Kev

MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Re: The dreaded wet cardboard taste

Post by MTW » Mon Jan 16, 2017 1:36 pm

Kev888 wrote:Purging by just squirting CO2 in may only be partially effective in any case, since CO2 does not actually displace oxygen (they can share the same space). Its mainly the through-draft that helps carry some oxygen out.
Not to add any weight to the oxidation theory in this case, but I tend to connect my CO2 to the 'out' post to purge, down the long dip tube, before filling, and release as much air (or at least diluted air-CO2) out of the PRV as it goes. Seems to make sense to purge the air through in one direction as far as possible. I'm sure Kev's right though, and you're basically 'diluting' the air with CO2 until the mix becomes so heavy in CO2, that the job is probably good enough. The CO2 will then settle to the bottom for a while, before mixing back with any air, as gases apparently do. So when you fill the keg from the bottom up, most of what is on top of the beer should be CO2 and push other gases out as it rises. Not perfect probably, but good enough. If you're ever in doubt, see if it puts a flame out just inside the rim when it's 'purged', which must be some sort of indication (?)
Busy in the Summer House Brewery

Matt in Birdham
Drunk as a Skunk
Posts: 764
Joined: Thu Oct 08, 2015 10:27 pm

Re: The dreaded wet cardboard taste

Post by Matt in Birdham » Mon Jan 16, 2017 2:20 pm

This article is an interesting read. One point of particular interest is the claim that paper/cardboard taste is a sign of hot side aeration, not cold.

I must admit that I have spent quite a bit of time recently down the rabbit-hole that is the HSA/LODO debate, which is currently ongoing on various other forums. I haven't formed much of an opinion on it yet, other than to think that there seems to be enough in it to give "low dissolved oxygen" brew day a try, just to satisfy my curiosity.

User avatar
Kev888
So far gone I'm on the way back again!
Posts: 7701
Joined: Fri Mar 19, 2010 6:22 pm
Location: Derbyshire, UK

Re: The dreaded wet cardboard taste

Post by Kev888 » Mon Jan 16, 2017 3:16 pm

The real-world effects of Hot Side Aeration seem to be far less dire than some used to believe, so in normal brewing practices it doesn't concern me much and certainly I'd say it was very unlikely to have created the OP's quite severe issue. However, it isn't a complete myth (there is some science behind it), so I wouldn't like to completely discount it as a contributor 'if' something fairly abnormal had occurred, introducing unusual amounts of air to the hot wort.
Kev

Matt in Birdham
Drunk as a Skunk
Posts: 764
Joined: Thu Oct 08, 2015 10:27 pm

Re: The dreaded wet cardboard taste

Post by Matt in Birdham » Mon Jan 16, 2017 3:38 pm

Kev888 wrote:The real-world effects of Hot Side Aeration seem to be far less dire than some used to believe
This really depends on what you read and who you believe. Just to be clear, I don't have a dog in this fight (haven't tried minimising oxygen on the hot side yet), but there is a lot of interesting chatter about it now. I'm yet to be fully persuaded by any of the internet arguments, but the most interesting thing to me is how many of the big breweries actually do go out of their way to minimise oxygen on the hot side - Sierra Nevada being one example (who apparently degas their mash liquor and mill wet under nitrogen).

User avatar
Kev888
So far gone I'm on the way back again!
Posts: 7701
Joined: Fri Mar 19, 2010 6:22 pm
Location: Derbyshire, UK

Re: The dreaded wet cardboard taste

Post by Kev888 » Mon Jan 16, 2017 3:55 pm

Yes, true, people do argue about the effects and magnitude of HSA. But the OP's results are so pronounced that I really can't believe normal levels/practices would be the cause, we would all experience them if they did. There would have to have been some unusual amount of aeration, IMO.
Kev

Matt in Birdham
Drunk as a Skunk
Posts: 764
Joined: Thu Oct 08, 2015 10:27 pm

Re: The dreaded wet cardboard taste

Post by Matt in Birdham » Mon Jan 16, 2017 3:58 pm

Kev888 wrote:Yes, true, people do argue about the effects and magnitude of HSA. But the OP's results are so pronounced that I really can't believe normal levels/practices would be the cause, we would all experience them if they did. There would have to have been some unusual amount of aeration, IMO.
Agreed - although it would be interesting to hear whether there was anything unusual about the mash, or whether the beer was tasted during ferment and showed any signs of oxidation.

BrewHouse

Re: The dreaded wet cardboard taste

Post by BrewHouse » Mon Jan 16, 2017 4:00 pm

To answer some of these questions:
It was in an airtight 5 gall wine fermenter fitted with an airlock
No, I didn't taste before kegging and so conceivably it could have been like this before I kegged but that would really astonish me as it was left completely untouched for 14 days. No peaking or fiddling of any kind. I did smell the FV and it smelt fantastic and so I just assumed all was ok and it was good to keg. Having said that, when I smelt the sample after kegging it did not smell of wet cardboard either. It smelt completely normal. I was a bit surprised that the taste could be so strong and yet no effect on the aroma.
No dry hopping and the keg was perfectly sealed. It was only in the keg for 5 mins before I had a test with a party tap.
HSA? The wort always stays in the boiler until the coiled chiller gets it down to pitching temp and so I doubt it but don't know.
I wouldn't claim to have the best ability to identify off flavours but this one is the wettest cardboardiest taste ever.

Am I right in assuming that this is always oxidisation?

MTW
Drunk as a Skunk
Posts: 905
Joined: Thu Feb 13, 2014 9:04 pm
Location: Just outside Scarbados

Re: The dreaded wet cardboard taste

Post by MTW » Mon Jan 16, 2017 4:13 pm

BrewHouse wrote:I wouldn't claim to have the best ability to identify off flavours but this one is the wettest cardboardiest taste ever.
Damn - I could have hopped over to taste a sample yesterday; I was in you neck of the woods, not that I'm fully qualified to comment. Some tastes are more obvious than others.
Busy in the Summer House Brewery

BrewHouse

Re: The dreaded wet cardboard taste

Post by BrewHouse » Mon Jan 16, 2017 4:36 pm

Matt in Birdham wrote:
Kev888 wrote:Yes, true, people do argue about the effects and magnitude of HSA. But the OP's results are so pronounced that I really can't believe normal levels/practices would be the cause, we would all experience them if they did. There would have to have been some unusual amount of aeration, IMO.
Agreed - although it would be interesting to hear whether there was anything unusual about the mash, or whether the beer was tasted during ferment and showed any signs of oxidation.
Nothing unusual about the mash as far as I can remember and no, I did not taste it at all during fermentation. I am a bit paranoid about infection and so tend to leave it alone until it is done. 14 days is much longer than I normally leave it in the FV but I had work commitments that meant I was not around. The brewfridge was already in use and so I had this in an insulated cupboard in the brew house with a couple of tube heaters set at 18C. I can't use this in the summer as it has no cooling but is ok in the colder months. My min max thermometer had packed up whilst I was away and so I don't have any idea of how stable the temp was. It certainly didn't go above 20 but we had some really cold nights and I have no idea how well the tube heaters coped at maintaining the temp. It seems unlikely that this could have anything to do with oxidisation.

BrewHouse

Re: The dreaded wet cardboard taste

Post by BrewHouse » Sun Jan 22, 2017 9:19 am

I just thought I would post a quick update on this.

I was about to throw this away yesterday and had another taste test just to be sure. The Cardboard taste had completely vanished. I feel like the little boy who cried wolf, but I know it was there a week ago and was overpowering.
I am completely baffled.

Post Reply