Yummm The Taste Of Wet Cardboard

[vlbaby]

Well the verdict is in, I have managed 2 consecutive brews that have a distinctive taste of wet cardboard. Problem is I dont know where its coming from.

I have done a few things different on these 2 brews that i havent done before. Firstly I have switched to fly sparging instead of batch sparging, and I am using an insulated keg instead of an esky.
I am also using a pump to move the wort around instead of gravity, and I have introduced a 0.5 micron air stone into the fermenter prior to pitching the yeast. Which by the way I am starting to wonder why an airstone doesnt oxidise a beer but splashing it during racking will? :blink:

Anyway, I am really disapointed with my latest brewing attempts ( as they are undrinkable, or at least drinkable under sufferance) , and would appreciate some advice as to what i may be doing wrong.




vlbaby.

 

[Ross]

Well the verdict is in, I have managed 2 consecutive brews that have a distinctive taste of wet cardboard. Problem is I dont know where its coming from.

I have done a few things different on these 2 brews that i havent done before. Firstly I have switched to fly sparging instead of batch sparging, and I am using an insulated keg instead of an esky.
I am also using a pump to move the wort around instead of gravity, and I have introduced a 0.5 micron air stone into the fermenter prior to pitching the yeast. Which by the way I am starting to wonder why an airstone doesnt oxidise a beer but splashing it during racking will? :blink:

Anyway, I am really disapointed with my latest brewing attempts ( as they are undrinkable, or at least drinkable under sufferance) , and would appreciate some advice as to what i may be doing wrong.




vlbaby.

[post="65897"][/post]​

The wet carboard taste indicates oxidisation - Will have nothing to do with the fly sparge or the air stone being used prior to pitching the yeast (oxygen generated at this time feeds the yeast - but at end of ferment will oxidise your beer). Are you moving hot wort around with your pump & is it cavitating (mixing with air)? If so this could be a possible cause - Otherwise I'm suspecting it is unrelated to your new practices & you may need to examine your whole process a bit more closely...

 

[ausdb]

Well the verdict is in, I have managed 2 consecutive brews that have a distinctive taste of wet cardboard. Problem is I dont know where its coming from.

I am also using a pump to move the wort around instead of gravity, and I have introduced a 0.5 micron air stone into the fermenter prior to pitching the yeast. Which by the way I am starting to wonder why an airstone doesnt oxidise a beer but splashing it during racking will? :blink:

[post="65897"][/post]​

This is the only one I understand enough to comment on, when you areate/oxygenate wort its not beer yet its wort and has just had all of the dissolved O2 boiled out of it so it needs ot be added for the yeast to work well. Once its fermented then its beer and oxygen contamintion becomes a problem.

For what its worth my last batch had bad diacetyl, I oxygenated the wort with pure O2 and made sure all of my transfers were CO2 blanketed (primary-secondary and secondary-keg) but the Safale droped ot of the primary after only 4 days which is what most people put it down to

Cheers ausdb

 

[vlbaby]

Once its fermented then its beer and oxygen contamintion becomes a problem.

Is oxidation of wort only a problem when its hot? Many people talk about not splashing the wort too much ie Hot side aeration.

Maybe it is the pump causing the aeration like ross suggested. Although I have done everything I can, some small pockets of air manage to become trapped in the pump for the first few seconds it runs. Problem is I dont know how to stop this.


vlbaby.

 

[davidp]

Hot wort will increase the rate of reaction because of the extra energy about. Wet cardboardy compounds don't get much of a chance with cool wort when the oxygen won't be around for very long (will be consumed by the yeast).

The others could comment better than I - but can't fly sparging be a problem if the sparge arm is too high up, if the wort splashes excessively or sprays too finely?

 

[Sean]

Once its fermented then its beer and oxygen contamintion becomes a problem.

Is oxidation of wort only a problem when its hot? Many people talk about not splashing the wort too much ie Hot side aeration.

Maybe it is the pump causing the aeration like ross suggested. Although I have done everything I can, some small pockets of air manage to become trapped in the pump for the first few seconds it runs. Problem is I dont know how to stop this.


vlbaby.

[post="65902"][/post]​

There are two possible "sources" for oxidation. The first is hot-side aeration. Disolving oxygen when the wort is cold won't be a problem, in fact is necessary, and the yeast will use up all that oxygen before it causes a problem.

The second possibility is oxygen getting in after the yeast has done it's stuff. Ie during racking, bottling, headspace in containers, etc.

 

[sosman]

Is oxidation of wort only a problem when its hot? Many people talk about not splashing the wort too much ie Hot side aeration.

Maybe it is the pump causing the aeration like ross suggested. Although I have done everything I can, some small pockets of air manage to become trapped in the pump for the first few seconds it runs. Problem is I dont know how to stop this.

[post="65902"][/post]​

I use a pump all the time and don't get wet cardboard. Do you run your airstone after fermentation and how long for?

Have you changed ingredients? Are you pitching big yeast starters? With or without starter liquid?

Aren't you glad you switched to fly sparging h34r:

 

[vlbaby]

sosman:

I use a pump all the time and don't get wet cardboard. Do you run your airstone after fermentation and how long for?

Have you changed ingredients? Are you pitching big yeast starters? With or without starter liquid?

Aren't you glad you switched to fly sparging

QUOTE]

I run the air stone for 10-15 minutes, with a fairly powerful flow from my air compressor.
The first brew i did was using safale s04 which i didnt rehydrate because i was lazy. I actually thought it was the safale that was the cause of the problem until i cracked open the following brew and found the same flavour.

The 2nd was a oktoberfest using a 2L starter of wyeast 2206. The starter was healthy is this case.
I have 2 more brews still in ferment at the moment. I wont be happy if these have been affected too


vlbaby.

 

[Sean]

At what point in the process did you notice the cardboard flavours, and what was the last point when it tasted ok?

 

[Trev]

It is more than likely that the wet cardboard is occuring post fermentation - Sean has well pointed out that aerating the wort when racking etc can cause this.

Are you splashing it around too much when racking and/or bottling? I get a bit paranoid about this and now purge my secondary fermenters with CO2 prior to racking.

One other thing to look at occurs if you're bottling the beer. If there's too much headspace (ullage) then it can bring onearly oxidisation. One way of counteracting this (other than charging each of the empty bottles with CO2) is to fill them fairly high and let them sit before you cap them. The theory is that whilst they sit they will release some CO2 from suspension and purge the headspace of air/oxygen.

If you keg your beer then have a look at your taps/fittings etc. I had exactly this problem and it turned out to be an infected tap. Even though I had run Idophor through it, there was black **** lodged in the bowels of the tap. I have two taps on the serving fridge, one was fine but the other produced two cardboard beers in a row!!!!!! I striped them down and found the sludge.

Trev

 

[WildebeestAttack]

I've just had two brews with the exact same problem.

Different brews with different yeasts, (both ales), and the same off smell. (The taste is okay, similar to previous brews with the same recipe, it's just a bad odour).

I did rack these an extra time and left in the secondary (thirdary) for an extra week because the ale yeasts were working a little slow due to cooler weather. (Possible to oxygenise during this time). However I never picked up on the taste until it was bottled. In fact they tasted good a few days before I bottled.

One thing I done different was when I bulk primed I used boiling water and then racked straight into it. Normally I would just use warm water to dissolve the DME, then rack into it.

Anyhow, I've been trying to work this out as well.

 

[vlbaby]

The first brew had just finished the primary fermentation when i first noticed somthing wrong. I allowed the beer to undergo 2ndry, cc'ing and kegging but it has not improved any.

The 2nd brew was a similar story except i thought it was just tasted too bitter because the beer had not matured. But it wasnt until last night after 4 weeks lagering and then transfering it the keg that i noticed that the flavour was indeed the same as the previous brew, cardboard after taste.

vlbaby.

 

[Vlad the Pale Aler]

Does your compressor/airstone set up have suitable filters ?
You may be pushing contaminated air from the compressor.
...my 2c worth.