Acetic smell from a Brett pitch (WL)

[OldDogBrewing]

I just opened a vial of Brett Trois Vrai from White Labs to make a starter for a brew I will make in a few weeks (when the brett is ready I will brew), the liquid was a bit dark in colour and when I opened it, it smelled really acetic, I expect it to be not acetic when I pitch only the slurry into the wort (it's for a 100% Brett ferm)

The thing is I also have a pitch of Brett C (Claussenii) and it has the same dark colour (probably oxidised?), I will use the Brett C to funk up a 1 Gallon batch of Tripel, how do I proceed with that? Do I make a starter to have enough slurry and just pitch the slurry? Do I take the risk and pitch the whole vial with the risk that it will give an acetic edge to the tripel as the batch is fairly small in volume? Or do I decant first the nutrients of the vial and just pitch the remaining small slurry?

 

[goodolarchie]

What's the date on those vials? They shouldn't be that bad. Generally you get funky, fruity aromas out of brett pitches, not acetic. I remember one WLP vial had managed to get down into the threads and smelled like vinegar, the cap was still sealed but must have come loose. I still used it after careful sanitation and it turned out fine.

If you are doing a primary with the Trois Vrai, it would make sense to prop it up, get it active and healthy pitch so the beer can take off quicker. You might check the pH of your completed starter, if it's dropping below 4.0 you may have some bacterial infection from the vial, but I wouldn't get too worried about a vial having a bit of acetic acid and I doubt anything is wrong with it. The starter should smell fine, with the acetic diluted.

You can direct pitch the brett C - even if it was a 10 gallon batch, pitch rate for a brett secondary is fairly negligible.

 

[OldDogBrewing]

What's the date on those vials? They shouldn't be that bad. Generally you get funky, fruity aromas out of brett pitches, not acetic. I remember one WLP vial had managed to get down into the threads and smelled like vinegar, the cap was still sealed but must have come loose. I still used it after careful sanitation and it turned out fine.

If you are doing a primary with the Trois Vrai, it would make sense to prop it up, get it active and healthy pitch so the beer can take off quicker. You might check the pH of your completed starter, if it's dropping below 4.0 you may have some bacterial infection from the vial, but I wouldn't get too worried about a vial having a bit of acetic acid and I doubt anything is wrong with it. The starter should smell fine, with the acetic diluted.

You can direct pitch the brett C - even if it was a 10 gallon batch, pitch rate for a brett secondary is fairly negligible.

The date is 11/7/20 which apparently is in american format which makes them old but not out of date. The vials were sealed but because of the acetic and the colour I would say that some oxigen managed to get in there. I made the starter 3 or 4 days ago, still no activity but there seems to be more and more slurry every morning (I don't have a stirrer yet), but temperatures are pretty low so it might be that the reason why it doesn't show apparent activity. I don't think there's anything else than brett, it smelled acetic like the time I forgot to refill the airlock of a brett saison for 2 weeks (that's not happening ever again)

What worries me about pitching the whole vial of Brett C is that the acetic liquid will give my beer an acetic edge when mixed as 1 gallon is not that much liquid if adding that quantity of acetic "wort" or whatever is in there, I haven't unsealed this one yet, maybe it's not acetic but it looks oxidised too

 

[goodolarchie]

I wouldn't be surprised if your old brett Troi Vrai vial takes a full 6-8 days to truly kick up. Some brett strains are very sluggish, which is why I suggested doing a nice active starter, you may even want to prop it up again before you go to pitch it.

What worries me about pitching the whole vial of Brett C is that the acetic liquid will give my beer an acetic edge when mixed as 1 gallon is not that much liquid if adding that quantity of acetic "wort" or whatever is in there, I haven't unsealed this one yet, maybe it's not acetic but it looks oxidised too

Then don't use the whole vial

And if you've managed to find two very acetic 100% brett vials from WLP, you might want to let your supplier/shop know that. I've opened a lot of brett vials in my time and the only truly acetic one was the instance I talked about above.

 

[OldDogBrewing]

I wouldn't be surprised if your old brett Troi Vrai vial takes a full 6-8 days to truly kick up. Some brett strains are very sluggish, which is why I suggested doing a nice active starter, you may even want to prop it up again before you go to pitch it.



Then don't use the whole vial

And if you've managed to find two very acetic 100% brett vials from WLP, you might want to let your supplier/shop know that. I've opened a lot of brett vials in my time and the only truly acetic one was the instance I talked about above.

I'm doing a 200ml starter for a 1 gallon batch but as it's for a high gravity wort (although brett won't finish the fermentation) I will probably step it up to 350 ml or maybe 400 ml

I've opened some vials with bacteria too and both the colour and smell is something I didn't found before, that's why I think the other one is acetic too, I think I will pitch half of it or something like that when it's beer is ready, if it's acetic too, I will contact him so he knows that probably he has some more acetic vials laying around, he got me the Vrai just for me so maybe they gave him something they had in a hidden corner somewhere haha

 

[OldDogBrewing]

Pitched today the Claussenii vial which was acetic too, decanted most of the liquid and pitched the slurry, my fermenter is sealed now and keeps bubbling so it shouldn't turn acetic the rest of the beer

 

[mashpaddled]

I wouldn't be worried about it. Brett can produce acetic acid in the presence of oxygen. Propagating yeast generally involves aerating to get growth over alcoholic fermentation.

 

[OldDogBrewing]

I wouldn't be worried about it. Brett can produce acetic acid in the presence of oxygen. Propagating yeast generally involves aerating to get growth over alcoholic fermentation.

The acetic went away when the starter was done, the esters covered it up and it hasn't appeared in the beer yet

Regarding the Claussenii vial, I had it vertical for two weeks so I was able to decant most of the liquid leaving a cake behind, now it's doing its thing in a beer