Off Taste - Maybe cardboard, maybe chemically - Not Sure

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Keviebaby

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Apologies in advance as this might get a bit long but bear with me.

I have identified the same off taste in my last two beers. It is almost, but not quite, medicinal and almost but not quite cardboard. It isn’t overpowering and if I tried I could probably still drink the beer but it is very noticeable and not pleasant.

The beers are a hoppy lager (bottled) and a hoppy bitter (kegged into a corny)

Common Factors
• Ingredients were purchased at the same time from the same supplier but no common ingredients between brews
• Both brewed using a grainfather and counterflow chiller
• Both fermented in the same plastic bucket
• Lager was bottled by way of a bottling bucket primed with boiled sugar syrup and taste was apparent after first tasting at 4 weeks. Did not taste before this so it may have been present earlier
• Beer was kegged direct from fermentation bucket with no priming sugar and taste was evident on kegging
• Lager is now 2 months old and beer has been kegged for 3 weeks and taste is still there although I do not think it has got any worse.

I’m really not sure what is causing this, however, I have for my last few brews been altering the mash PH using CRS and associated chemicals (gypsum etc) as appropriate for the beer style. This does rely on the water report that I have being correct but I do also check the PH with litmus strips and a PH meter and the Mash PH is generally between 5.2 and 5.4

For a full clean I use VWP and believe I rinse appropriately (until no chlorine smell) I have been brewing on and off for around 20 years so do understand the importance of this.
For brew day sanitation I use Star San made up with Tescos Ashbeck water.
Fermentation takes place in my spare room. No brew fridge but cool.

My next steps are:
• Deep clean of grainfather. I clean using grainfather cleaner after every brew but have not yet checked the pump for potential contamination. Will strip down pump and ball valve and ensure no matter is stuck anywhere in there.
• Deep clean of fermenter. I do this after every brew anyway. There are no apparent scratches on the plastic and the bin is relatively new (less than 1 year old).
• Brew using grainfather but cool using immersion chiller rather than counterflow chiller. I can’t physically inspect the insides of the counterflow chiller. It is cleaned after every brew when I do the grainfather but if I use the immersion chiller I can eliminate the potential of this causing some kind of contamination.

I know that cardboard taste can be due to oxidation and am careful with splashing after fermentation but am open to any suggestions on minimising this.
I was going to start using a pump and airstone to introduce more air into the wort prior to pitching the yeast but will hold off on this until I bottom this out, unless anyone thinks this may be due to inadequate aeration?

Also, I am fully prepared to accept that despite what I think I am still not rinsing the cleaner off my equipment well enough so will be extra careful next time but I did get a mail through about a new cleaner ‘Bruzyme’. It’s not clear if this is a rinse free cleaner but it looks like it might be. Anyone tried it?

Sorry this is a bit rambling but any ideas or suggestions would be gratefully received.
Cheers
 
All sounds fine to me so I`m thinking fermenting temps maybe the culprit.

What yeast are you using?
Does the spare room temp fluctuate?
 
Cheers,

Yeast was Mangrove Jacks Bohemian Lager for the Lager and US-05 for the bitter. Temperature will have fluctuated so I am just guessing to a certain extent but I think between 12 overnight and 16C during the day for the lager (I did it when I knew it would be cold outside - MJ say yeast best between 12 and 15 so may have got a bit high) and maybe a maximum of 19C for the bitter.

More difficult to test temperature effect until I get a brew fridge sorted out. Space is my enemy there at the mo.

KG
 
That counterflow chiller sounds about the only part that hasn't or can't be cleaned, I'd leave it out on the next brew.
 
A papery, cardboard taste is associated with a compound called trans-2-nonanal and is caused by oxidisation or ageing of beer.
The medicinal flavour (TCP?) is associated with a wild yeast or a sterilant contamination. Be aware that if it is wild yeast that Starsan may not kill this off
Looks like you may have two separate things going on there.
 
Thanks for the replies.

I've just finished examining the pump and the pump itself looks fine but when I took apart the ball valve there was a bit of a funny smell and when I looked at the spring there was something (couldn't tell what:sick::sick::sick: either hop or grain) wrapped around the coil of the spring which didn't look good.

Taken it apart and got it soaking in some cleaner at the minute. I think I will use the immersion chiller this weekend though and see what happens.

KG
 
I have had that TCP taste before and its smells horrible as well. Had to ditch it so i always taste now before bottling. Took a long time for the smell to fade from my FV even after bleaching. Have reused them though with no problems.
 
Has mention it sounds like those different fermenting temperatures are mostly likely be the cause. A steady temperature improves the beer loads. A trug of water with an aquarium heater doesn't take up mi h space and can be put away when not using it
 
A papery, cardboard taste is associated with a compound called trans-2-nonanal and is caused by oxidisation or ageing of beer.
The medicinal flavour (TCP?) is associated with a wild yeast or a sterilant contamination. Be aware that if it is wild yeast that Starsan may not kill this off
Looks like you may have two separate things going on there.

+1 - what geetee says.

TCP also caused by using chlorinated water, but your use of tesco ashbeck rules that out.
 
This is definately a case of fluctuating temps stressing the yeast and causing the off tastes.

Firstly you need to invest in some temperature control either a water bath and aquarium heater or heating pad and Inkbird. I fully understand the fridge part, I`m in the same situation, no space.
Secondly once you have the control set it to the higher degree of the room in the daytime so it will maintain a constant temp or thereabouts (+/- 1 degree should be fine),

I have had both these of tastes in a beer that I puposely pushed the temps too high. What can I say, I like to gamble as long as I don`t mind losing. First it had a cardboard taste and nothing to do with oxidisation (was almost drinkable) then it gained a medicinal taste so I threw it down the drain.
I also had a pilsner brewed in 2011 with a TCP taste, same medicinal taste, tastes a little better now but I wouldn`t buy it hehe, gonna keep it a few more years and see what happens.
 
I had the TCP taste a couple of times and put it down to not using a campden tablet. Sounds like you have been brewing for years so I expect you already treat the water.
 
Just to update a bit on this thread. As mentioned I did a strip down on my grainfather and found that the spring in the ball valve was full of horrible looking and smelling gunk.

Cleaned it all out, made sure it was sterile and did a brew last weekend, a Deuchars IPA clone. Took a gravity reading this morning, 1.009 so will be kegging in the next day or two.

Had a good smell and taste from the sample and, fingers crossed, I couldn't detect any of the off taste that I described in my original post so fingers crossed that the good clean has done the trick.

Got to remember to check all the nooks and crannies though. Took the ball valve apart again after the last brew and there was more stuff gathering around the spring again.

Thanks for all the responses guys.

KG
 
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