Stopping a long fermentation

[jceg316]

I have an imperial stout I brewed a couple months ago now and is still fermenting. There's definitely something wrong with the yeast as I've hadthis happen before, and when I tasted it it had a really nice flavour giving way to an alcoholic flavour. I put oak cubes and cocoa nibs soaked in brandy in there for a while and now it tastes like a chocolate barleywine aged on oak, really nice!

I want to stop fermentation, can I chuck in a campden tablet or will that have other ill effects?

TIA.

EDIT: It's fermented past its FG.

 

[Drunkula]

Potassium sorbate + campden are used for wine if anyone else needs to do this:

https://www.wilko.com/en-uk/wilko-wine-stabiliser-30g/p/0022657

 

[JonBrew]

If you use potassium sorbet or campden to stop fermentation you'll need to force carbonate as those agents work by killing/inhibiting the yeast.

What's the current SG?

 

[jceg316]

If you use potassium sorbet or campden to stop fermentation you'll need to force carbonate as those agents work by killing/inhibiting the yeast.

What's the current SG?

My plan was to add yeast before bottling, I have quite a few in the fridge. The current SG is <1.012, haven't measured in a while. Still pretty low for an imperial stout.

 

[JonBrew]

I'm not sure if adding fresh yeast, after already introducing a stabiliser, would work. I could be wrong though as I have no direct experience here.

If you want to avoid the stabiliser route and slightly under-prime and bottle in heavy duty champagne style bottles. Appreciate this is a bit of a punt though.

Are you able to rule out a wild yeast presence?

 

[William Smith]

how do you know it's still fermenting?
what was the starting gravity and what temperature are you fermenting at?
a couple of months does not sound plausible to me at all

 

[jceg316]

I'm not sure if adding fresh yeast, after already introducing a stabiliser, would work. I could be wrong though as I have no direct experience here.

If you want to avoid the stabiliser route and slightly under-prime and bottle in heavy duty champagne style bottles. Appreciate this is a bit of a punt though.

Are you able to rule out a wild yeast presence?

Yes. It took a long time to ferment down to the FG. TBH I often find my beers ferment past the calculated FG.

 

[Zephyr259]

I'm not sure you can if you're bottle conditioning as anything that will stop the fermentation will prevent bottle conditioning. The Mad Fermentationist made an Imperial Stout which finished at 1.030, pitched Brett C and let it come down to 1.020 where he added 1 campden tablet per gallon, cold crashed, fined with gelatin and transferred to a clean carboy to try and knock all the brett out. It worked and it was stable at 1.020 which he then bottle conditioned with a wine yeast I think (he tend to do that).

You could try similar and then pitch a low attenuating yeast or a wine yeast at bottling? Don't use sorbate as once that's added no additional yeast will help as far as I'm aware.

Good luck.

 

[jceg316]

After reading around I'm not sure I do want to stop fermentation. I think using a campden tablet or something similar will probably cause more hassle than it's worth.

This yeast is struggling because it's a high gravity beer and I underpitched. I could put more yeast, I don't have the same strain anymore but might be interesting to pitch a different yeast.

Alternatively I might just wait. I'm a bit worried the yeast is in there making bad flavours.

 

[parpot]

That Stout brew sounds great and very interesting, hope it turns out as good as it sounds