Scotch ale isn't carbonating: What's my next step?

Back in January, I did a 3 gallon batch of the wee heavy recipe from Brewing Classic Styles. Everything went according to plan, but in the many, many weeks since bottling I still haven't managed to get much by way of carbonation. I originally bottled at the end of February and left the bottles in the basement (temp around 63F) for about a month. At that point, the bottles that I tested gave a slight hiss, but had very little carbonation. I decided to move the bottles upstairs, where the temperature was about 72F, and rouse the yeast before letting them sit for another month. I tried one yesterday and it didn't seem any better than the ones I had tested in March. At this point, I figure the problem is either faulty capping, or else the yeast is having a hard time dealing with the 9.5% ABV. I bottled in a mix of 12 oz and 22 oz bottles, but I'm not sure how good the seals are on the 12 oz bottles (the size I have been using for my testing). I'm going to sacrifice a 22 oz bottle soon, and if that one is flat then I'll know it isn't the caps that are causing the problem, because my capper has a very good track record with those bombers. I should know within a day or two, as soon as the urge to drink a Scotch ale strikes me again.

So assuming that I need to add fresh yeast to my beer, what's the best way to do it? What kind should I buy, and how much should I put into each bottle? It would be a shame to lose this batch, it's pretty tasty even without carbonation - but I can't see myself drinking bombers of it flat. Next time I make a big beer like this, I'm just gonna keg it...

 

Unfortunately, I didn't note how much sugar I used, but I doubt that's the problem. I always use the carbonation calculator on the Northern Brewer website (it's the first one that comes up on Google!) and I'm pretty used to dealing with sugar in those amounts (I measure in grams using a digital scale). I know that I racked onto the sugar solution and stirred at least when I started bottling, though probably not halfway through the process. But with a 3 gallon batch, it doesn't take very long to bottle and I doubt there was too much of a difference in sugar concentration between the bottles. Opening a bomber will help me verify this, because I filled all my larger bottles first and then did the smaller ones after.

If I wind up re-yeasting, does it matter what kind I use? I thought I might need a champagne yeast, but would US-05 do the trick just as well?

 

I used Wyeast 1728 Scottish Ale for this one, which claims to have 69-73% attenuation. Can you recommend a dry yeast to follow that up with that wouldn't over-attenuate? What about Red Star Premier Cuvée?

 

That looks good, but I'm not sure where I can get it in Canada. The reason I mentioned that wine yeast is because it's available at the store where I was planning on placing my next order. Why would it be bad if the wine yeast killed the original pitch? Because it will stop the conditioning process?

 

Sounds like the decision is unanimous, huh? Thankfully, I found a homebrew shop in Canada that carries CBC-1, so I'll be ordering some if my bomber turns out to be flat. Thanks to everyone for the advice, hopefully I'll be able to salvage about 2/3 of this batch.

 

So if anyone is interested in an update, I received my CBC-1 yeast several weeks ago and finally got around to re-pitching...last night. By my count, it has been over three months since I bottled this beer, and it has been upstairs in the warmer temperatures for the last two of those. Anyway, I started opening my bottles last night, only to find that the "hiss" had gotten significantly louder. In fact, depending on the bottle, it varied from "pretty quiet" to "champagne cork" (for some flip-top growlers I have). I decided to drink a sample from a warm 12oz bottle, and while it was a little undercarbonated for the style, it was much better than the last one I tried. Starting to think that my priming sugar wasn't as well-mixed as I thought, though, because the larger bottles seemed to have a lot more pep. In the end, I decided to add yeast to the bombers and growlers, but the 12oz bottles didn't seem worth the effort. I'll let them sit another week or two, but I think a lot of these bottles are already carbonated and ready to drink. I put one of the flip-tops into the fridge, so next time I have some guests around I'll give it a try and see how it's doing. I guess the lesson here is to give big beers a really long time to carbonate - or to just keg the damn things and be done with it.

 

Last night I had some of this beer and it was (gasp) carbonated! Or at least, the flip-top 750mL bottle that I tried was. I also opened a 330mL capped bottle, and that one was still less carbonated than I wanted. Could it be that there isn't enough yeast in a smaller bottle to properly carbonate a high ABV beer like this? Either way, I'm happy that at least part of this batch will end up drinkable (and pretty tasty, based on the glass I had yesterday). I'll post a pic in WHBAYDN next time I have some.