Can I repair a flat imperial stout in bottles?

[element533]

Bottled a 10.5% imperial stout with priming sugar according to the normal calculation, but I think the yeast were dead or something because the beer is flat after 4 months in the bottle at room temperature. There is very light lacing on the glass, but no visible carbonation and nothing discernible on the tongue.

Can I repair these beers by opening the bottles back up and re-priming them? What's the best method to do that? I suspect the priming sugar is still present in the bottles (since it obviously didn't get converted into CO2). Does that mean I only need to add yeast and no sugar? How much?

Thanks in advance!

 

[Easycreeper]

Yes, you can add fresh yeast with a high alcohol tolerance assuming the priming sugar is still present. I've used both champagne yeast and wine yeast (premiere cuvee) to bottle condition. Most recently was a quad where I added dry yeast directly to each bottle and recapped.

There is one thing to keep in mind, however. If for some reason your caps didn't seal, the priming sugar was likely consumed and the CO2 escaped. You'll have to reprime if that's the case and go about adding more yeast. Does the beer taste fairly sweet from what you recall when you took your FG sample? If it does, the priming sugar is probably still there. Experiment on one bottle before you tackle the whole batch. Wine yeast is cheap...

 

[element533]

Yes, the beer does taste sweet. I think I will add yeast. How much should I add? Is it better to empty all the bottles into a container, mix with the yeast, and rebottle them all? Just thinking of how to make each bottle consistent...

 

[Easycreeper]

Yes, the beer does taste sweet. I think I will add yeast. How much should I add? Is it better to empty all the bottles into a container, mix with the yeast, and rebottle them all? Just thinking of how to make each bottle consistent...

Only a few grains per bottle. Definitely don't dump everything out and mix the yeast in. You'll oxidize your beer that way.

Just try one bottle for now to ensure you don't need to reprime. Wine yeast should show results in a couple weeks. If it looks to be working, go ahead and add yeast to the rest of the batch.

 

[element533]

OK, update.

I tried a couple bottles with Premiere Cuvee. In one bottle, I put 10-15 grains of yeast in, and in the other one I put about 50. Both of them carbed up slightly, but still not enough. Should I try again with more yeast??