Ok…call us crazy, but one of the brewing partners wants to make a double-bock type beer.
And, we have a very nice (fresh) Kolsch yeast slurry, maybe a quart or a little more.
This probably goes against all of the rules, but has anyone made a bock, but used an ale type (Kolsch) yeast? Is there any reason we should not attempt this?
I say Go For It! If I’ve learned anything from this crazy hobby, it’s: “The only real constant is change”. Without experimenting, we would never have soooo many wonderful beer styles we currently enjoy! Besides, if you have a slurry ready to go, you’ll certainly save a little money if you use it. And, who knows, you and Bel Air Brewing May be on the cusp of the next beer craze!
Of course you can do this, however, using a Kolsch yeast (not sure which one you’re using)will leave a more estery, fruity beer. I like my double bocks to be huge malty, rich beers that are clean with good attentuation. I think the key is getting good attentuation which makes the beer drinkable without any cloying sweetness.
To me, the flavor profiles are so far apart that I wouldn’t be tempted to try it.
The goal is not to copy an existing beer profile. But to see what happens with this combination.
Wyeast Kolsch. We would ferment cold, probably below 56 F, maybe 50 F.
Well, then, go for it! 2565 in a beer like that doesn’t sound good to me, but I’m not the one who’s gonna drink it.
Maybe you could do a split batch. Try one with the WY 2565 and another with a lager yeast.
Or a clean ale yeast like 1007.
Technically it won’t be a doppelbock if brewed with an ale yeast, but call it what you like :-X.
Once again…trying to please the wife of a brewing partner. And, use this very fresh Kolsch yeast slurry that is ready to go. She likes a Kolsch, but REALLY likes the Spaten Doppelbock beer.
Trying to find a happy medium. We are not looking to conform to any BJCP guidelines here.
When you make the rules, you can break the rules!
To my taste imagination, I don’t care for the combo of fruity/winey yeast and the heavy malt character of a dopplebock. Which is not to say that others won’t love it.
Ok. The Kolsch we just brewed was pretty clean in profile. I would not call it fruity at all. But only had a 1/2 oz sample, and it is still aging.
How about an Amber Kolsch? Might that work?
To my mind, that might be more successful.
FYI I have not had good luck fermenting higher gravity batches with kölsch yeast. The beers turned out … odd. Almost “belgiany” with “tripel” like esters. Now, to be fair, I only tried it a few times but I personally did not care for the results.
Will the Kölsch yeast ferment the maltotriose? Most ale yeast do not, I believe. But it’s only beer, so what the heck, give it a try…
Good info. We may have a change up in the yeast, or the grain. Wanted to use this fresh slurry, but not brewing another typical Kolsch.
Bingo!. In my opinion, it will be what you make it. If you don’t want the ester profile, ferment at a lower temperature. Otherwise, ferment at a higher temperature and enjoy a malty fruit salad! Either way, it’s your beer!! I’m anxious to hear how it turned out! Good luck! 
I get a lot of esters with 2565 even at lower temps. But I have limited experience with it.
Looking at making a German Alt Beer. With the 2565. Wyeast recommends this yeast for this beer style.