October 23, 2018

Can You Ferment a Maibock with Ale Yeast?

Let me introduce you to each other. Sustainor 2, these are the homebrewers. Homebrewers, Sustainor 2. S2 is a non-traditional rye Maibock (psst … don’t stare at its dry hops and red color, it’s self-conscious), and one of NB’s limited edition beer kits for the first three months of 2012.

This ryed-up reboot of last winter’s limited edition bock recipe is built as a lager, and uses one of my favorite lager yeast strains of all time: Wyeast 2487 Hella-bock, which is only around January through March this year. But even if you don’t have the refrigeration or ambient temps for a proper lager’s cold fermentation, don’t deny yourself the pleasure of brewing this kit and thumbing your nose at the Reinheitsgebot a tiny little bit. Hey, just kidding, Reinheitsgebot, I love you. But I’m still dry-hopping this too-dark rye Maibock.

I set out on a frosty morning to split a 10-gallon extract batch of Sustainor 2 and try out a couple ale-ternative fermentation strategies (pun intended, and I’m not sorry). Standard business of steeping, boiling, and hopping. Wort was chilled to ambient basement temp of 66 F, drained into separate carboys, oxygenated, and then:

S2-A: Fermentation with US-05

A clean-fermenting ale yeast: the pseudo-lager brewer’s best friend. It’s still important to minimize fermentation character by keeping temps on the cool side, providing lots of O2, and using a high pitch rate - I used two packs of dry yeast for this five-gallon half of the batch.

Primary fermentation at 66-68 F. 18 hours after pitching, it was at high krausen and the airlock perfumed the basement with a spicy-herbal mix of Sterling hops and rye.

S2-B: Fermentation with Wyeast 2124

Yeah, this is a lager yeast - Bohemian Lager. Once, over pints, my homebrewing friends in the lab at Wyeast confided something counterintuitive: they have had good results brewing lager-ish beers using this strain fermented at ale temps. Whaa? Let’s make a 1500 mL yeast starter on a stir plate and give it a shot.

Primary fermentation at 66-68 F.  Very vigorous with lots of rotten-egg sulfur coming from the airlock 18 hours in - it being a lager yeast, I took this aroma as a good sign.

At 72 hours, the krausen in both carboys went from rocky to creamy as the CO2 slowed down, and the airlocks started to offer hints of what the finished beers might be like: even before the dry hopping, US-05 continued to show off the gently fruity spice profile of Sterling, while 2124 started to give up its sulfury ways and make malty promises to my nose.

After 12 days (that’s another hot tip for pseudo-lagering - allow plenty of time in the primary fermentor so the yeast cells have a chance to reabsorb diacetyl and its kin, to make as clean a profile as possible in the finished product), the batch was racked onto the dry hops in a pair of sanitized 5 gallon carboys. The 2124 half was surprisingly clean and quite bocklike - malty and rich with a halo of young-lager sulfur; and true to its aroma, the US-05 half highlighted the rye and hops - very spicy, pretty biscuity, with a candy-apple caramel malt and citric hop bonus. The carboys sat as the deepening winter brought ambient basement temp down into the low 60s.

And after the appointed time: into kegs with matching FGs of 1.014, and after some more appointed time: into the glass. Both are garnet-red with pretty good clarity … let’s take a little sip:

S2-A: Tasting with US-05

Aroma is fairly clean, but not lager-clean. Much juicier and less bready than 2124, but it plays up the hops and rye more. Upon tasting a big immediate wave of rye and Sterling spice - minty, herbal, and tongue-coating - with a long rye-dominated middle and a hoppy, slightly warming finish. Slick, oily, oatmeal stout-like mouthfeel - that’s the rye. Reminiscent of a rye IPA or American rye red ale, but with an unexpected hop variety.

S2-B: Tasting with Wyeast 2124

Aroma is very malty and bock-like, with toasty and sweet caramel notes plus a whiff of authentically lager-ish sulfur, plus some non-authentic esters - but not really far enough above threshold to distract, and it’s a non-traditional beer anyway.  A bit of spicy rye mixed in with the other malts, hops are downplayed compared to US-05. In taste: balanced! The same rush of flavors - rye phenols, mint, herbs - but they don’t trample the tongue, held in check by the malt. Rich, fat, and oily in the middle with a surprisingly hoppy finish. Warming note is absent - abv% better hidden than with US-05. Overall I think this batch, with its more prominent malt character, is more true to the idea of a bock than US-05.

So at this point I guess we need some conclusions:

  • both batches are very tasty, although quite different from one another (and from the same recipe, fermented cold with Wyeast 2487)
  • US-05 was less bock-like, but a bit easier to work with and keg- or bottle-ready earlier, and my hophead friends who tried both batches preferred the heavier Sterling accent in this beer
  • for 2124, I hypothesize that a true lager fermentation would have lowered the ester profile even further and smoothed out some of the rough edges, but this is definitely tasty and I’d try this warm-fermented approach again on this or other dark and/or strongly-flavored lager recipes

For more info, check out our video: Maypole Maibock Lager | Behind the Brew