Bottling my Imperial Stout

why is champagne yeast not ideal?

 

You don't want bottle bombs... so use something that only eats simple sugars (and not more of the maltotriose than your primary strain did).

You don't want undercarbonated beer... so use a strain that will eat all of the simple (priming) sugar without succumbing to the ABV.

Champagne yeast fits these requirements. Otherwise...pick an ale strain that's less attenuative than your primary strain and highly alcohol tolerant.

 

I would recommend Champagne yeast for this beer since it is so high in alcohol. Below is a posting from Bill Pierce on another beer forum (Bill Peirce really knows his stuff!).

“I prefer champagne yeast for its higher alcohol tolerance if the beer is above 10 percent ABV. Concerns that the yeast will ferment the beer too dry are misplaced; the yeast will happily metabolize the easily digestible priming sugar and leave the much more stubborn dextrins alone that contribute to body and mouthfeel.”

Cheers!

 

What I would do;
I'd take 16 oz of it and put it into a 16 oz plastic bottle and add the recommended table sugar and know for sure in a week or two if I needed to re-yeast.
Edit: The reason I'm suggesting plastic so you can easily just give it a squeeze ever few days to see if anything is happening.

 

I had the same issue about 5 months back. Go find the Danstar CBC-1 yeast. Worked like a charm.

http://www.danstaryeast.com/products/cbc-1-cask-and-bottle-conditioned-beer-yeast

 

This yeast has saved 2 batches of 'under'carbonated old ale. I will use this for future stouts/old ales that have secondaried for a considerable amount of time.

 

Champagne yeast strains cannot, repeat cannot, use maltotriose. It's not that they can't use it 'easily.' Assuming your primary yeast did not poop out before it finished, there will be no 'lower' sugars left. What was your primary strain anyway? If you are sure your fermentation finished, why not use that?

 

I bought CBC-1 at my LHBS, which has an online presence.

http://www.keystonehomebrew.com/

 

If you're worried about a champagne yeast over fermenting you should pitch it in your fermenter about a week before you rack to your bottling bucket. There'll be plenty of yeast in suspension for the carbing and it will have a week to hang out in your RIS in case it wants to drop your FG a few points. I'd definitely rehydrate a dry yeast before pitching it and I'd definitely pitch more yeast.