Getting Rid Of Acetaldehyde

[Steve@PMF82]

Well after sifting through the great debate in this thread, I'm wondering if we can get some good discussion on the topic of how to get rid of Acetaldehyde?
Granted that it may be caused by oxygenation or poor yeast conditions.

I'm not sure what has caused the Acetaldehyde in my brew. I pitched it onto the cake of a previous beer (so enough yeast cells) and left it there for 2 weeks at 18-20deg (which should have been long enough for yeast to finish and clean up?). I then chilled it, after 2 days added gelatine and 2 days after that kegged and force carbed.
The fresh fruit/green taste didn't really show up until recently (few days in the keg), I'm quite sure it wasn't there in the fermenter early on, but I didn't sample from after 1.5 weeks from pitching to after kegging.

What are some ways of getting it to clean up? It was chilled in the fridge, so I've taken the keg out and left it in the garage to warm up and hopefully help the flavours balance out a bit quicker.

As I was reading this thread I found this, which moosebeer had come accross. Anyone tried it? I'm thinking of attempting to burp it a bit for a few days if that might help.

I've also had a beer, a pils using S189 that never got rid of this flavour. 4 weeks in fermenter and 4 weeks in keg and still had that flavour.

Did we establish that you probably had aceto infection in other thread?

Granted you may be talking about different beers? If so it could be that your other beers have a less severe mild infection and that is what you are tasting? and not Acetaldehyde

Just a theory, maybe see if you can get an experienced taster to taste it?

 

[Acasta]

Sadly, a different beer...

Different everything actually. Hops, yeast, malt, fermenter, time of brew. All different, but still 2 with Acetaldehyde and one with solvent taste (which we determined an infection).

1/4 kegs are drinkable but haha <_<

I've even started re-reading 'how to brew' chapter one to see wtf is going on. After fermenting for 2-3 weeks I have no idea what these beers are picking up these flavours.

 

[Steve@PMF82]

I would start by nuking everything with various chemicals and heat. Get new / fresh yeast and pitch lots of it.
Look into how much O2 you are introducing in your process after ferment.

 

[drsmurto]

SO2 reacts with acetaldehyde so if you have any potassium metabisulphite i would start dosing that in - 20 ppm total at a time (use an online SO2 additions calculator).

 

[MHB]

You might try carbing and venting the keg a couple of times, a lot of volatiles can be stripped out this way. Still not as good an answer as preventing it in the first place, but it might help.
Mark

 

[Helles]

If the bad flavours are leaving the keg via venting so are the good ones

 

[Acasta]

I would start by nuking everything with various chemicals and heat. Get new / fresh yeast and pitch lots of it.
Look into how much O2 you are introducing in your process after ferment.

Getting new fermenters and transfer lines and a stainless spoon, so thats everything cold side replaced. Will nuke the fridge and kegs too before filling them again.

SO2 reacts with acetaldehyde so if you have any potassium metabisulphite i would start dosing that in - 20 ppm total at a time (use an online SO2 additions calculator).

Unfortunately no, I'll see how it goes with some more age then maybe source some.

You might try carbing and venting the keg a couple of times, a lot of volatiles can be stripped out this way. Still not as good an answer as preventing it in the first place, but it might help.
Mark

Kegs are carbes and I have them warming up now so I'll vent a bit of carb over a few days and keep it topped with co2

Definitely looking to prevent it occurring again. As Beer4U mentioned, I'll be careful with yeast pitching rates, and watch for splashing during transfer.
I will also look at better aeration of the wort prior to pitching so help the yeast finish up in the fermenter.

 

[mr_tyreman]

I had a run of Acetaldehyde beers recently, everything i read said yeast, sanitation and 02.....after trying all these i still had the issue, i finally figured out my issue, it turned out that i had not seled up my fermenters properly post fermentation. So as the C02 had stopped being created by the yeast, the air outside the fermenter had equalised inside the fermenter and oxidised the ethanol giving a Acetaldehyde type flavour.

So make sure (if you dont) that you seal up the fermenter to stop any transfer of air into the fermenter, use airlocks, rubber bung, glad wrap....anything to really get an air tight seal on the vessel.

not gospel, just my experience

cheers and good luck

 

[Acasta]

I had a run of Acetaldehyde beers recently, everything i read said yeast, sanitation and 02.....after trying all these i still had the issue, i finally figured out my issue, it turned out that i had not seled up my fermenters properly post fermentation. So as the C02 had stopped being created by the yeast, the air outside the fermenter had equalised inside the fermenter and oxidised the ethanol giving a Acetaldehyde type flavour.

So make sure (if you dont) that you seal up the fermenter to stop any transfer of air into the fermenter, use airlocks, rubber bung, glad wrap....anything to really get an air tight seal on the vessel.

This is something I had not considered yet. How long after fermentation do you recommend adding the lid? With an airlock still fitted or could it be without?
Thanks

 

[MastersBrewery]

Having read through some of the comments regarding oxygen permeating all but preasurised vessels, leaves me wondering why so few have moved to ss preasure vessels to ferment in. Dont get me wrong I know connicals cost the earth, but a 50l keg is about the same shape as what most of us use now and a simple adjustable preasure relief valve could keep your ferment at say 4 or 5 psi. I note this was brought up on HBT a while back and some now have even used cornies to ferment in.

 

[labels]

I recently kegged two and a half kegs from the same batch that were fermented in two fermenters (50L batch). The half keg had some from each fermenter in it.

Now, strange as it is, the half keg tastes like a granny smith orchard while the two full kegs have no acetaldehyde whatsoever!

I'm putting this down to an infection possibly. The other cause maybe is I soaked one keg in a bleach solution to rid a mouldy problem. Although I rinsed and rinsed and rinsed and finished off with a mild acid solution (phosphoric) to re-pacify the metal, it still could have caused a problem if that was the keg in question.

In any case, I am suggesting that (1) acetaldehyde could have more than one cause other than immature beer or beer taken off the yeast too soon and (2) the taste could be something else completely that's being put down to acetaldehyde when it is something quite different.

 

[jc64]

I had a run of Acetaldehyde beers recently, everything i read said yeast, sanitation and 02.....after trying all these i still had the issue, i finally figured out my issue, it turned out that i had not seled up my fermenters properly post fermentation. So as the C02 had stopped being created by the yeast, the air outside the fermenter had equalised inside the fermenter and oxidised the ethanol giving a Acetaldehyde type flavour.

So make sure (if you dont) that you seal up the fermenter to stop any transfer of air into the fermenter, use airlocks, rubber bung, glad wrap....anything to really get an air tight seal on the vessel.

not gospel, just my experience

cheers and good luck

You sure did, and apparently so did I. I've given up on my 'open ferment' experiment. My ABA will be just out of the FV by next club night so I'm going to try and carb a bottle for your critique, be gentle! :lol: :lol: