As you may notice, I don't spend a lot of time trying to 'clone' commercial beers. I definitely get why you would — being able to brew a duplicate of your favorite (rare, expensive) commercial beer can be extremely convenient, and money saving. But for the most part, it's not what appeals to me about homebrewing. However, after reading an interesting feature about John Kimmich — brewmaster at Vermont's The Alchemist, maker of Heady Topper — where Kimmich attributed part of the huge fruity aroma of Heady Topper to his own proprietary yeast strain... I knew that was something I wanted to look into. Not to clone a beer I love (though eventually, I attempted a Heady clone with my homebrewing club), but to dissect and examine one of the components that makes the aforementioned beer great. Because if you know anything about me, you know that I consider two things to be best in life: 1). to crush your enemies, see them driven before you, and hear the lamentations of their vomen, and 2). Heady Topper. So was I going to culture this yeast for my own nefarious purposes? F*** yeah I was.
So here's what I learned about Conan, The Alchemist's proprietary yeast strain.
When brewing an IPA, most brewers reach for a clean, neutral yeast strain with decent attenuation. IPAs are all about hops, and the idea is to use a yeast that won't get in the way, that will ferment cleanly so the hops come through clear. But what if you had some sort of secret weapon: a yeast that has both phenomenally high attenuation, yet creates a clean, creamy mouthfeel; a yeast that doesn't muddle hops flavors, but rather enhances them? It seems that is exactly what The Alchemist has done. In John Kimmich's own words: “The heart of the beer is my private strain of Conan ale yeast. It produces very distinct apricot and tropical fruit esters, but you have to know how to handle it, how to draw the character out.”
I started with two cans of Heady Topper, fresh from a trip to Vermont. The Alchemist makes no secret of the fact that Heady Topper is unfiltered — a term which just indicates that the brewery hasn't filtered out the yeast. For a homebrewer, super fresh and unfiltered translates to easy yeast culturing. Ten years ago, who the hell ever thought people would be drinking world-class beers out of cans, much less culturing yeast from them?
When propagating yeast from a commercial beer, you want to start out with a very small, low gravity starter to give the yeast a foothold. Culturing from a bottle or can demands that you "step up" your starter at least twice before you're ready to brew. So this is what I did: about 10 ounces or so of 1.040-ish wort. I poured about 80% of a can of Heady Topper into a glass for consumption, swirled up the rest, and poured the dregs into the starter. Repeated later with a second can. For obvious reasons, the more cans (and more dregs), the better.
Boom. A day or so later, I had a respectable ring of yeast sediment at the bottom of the starter. The freshness of the original beer was a huge help in avoiding lag time. From there, it was a simple matter to step this up to a normal, pitching size starter, after which I decanted off a small portion into a sanitized jar for later usage. Then I pitched the majority of the starter to the IPA I was brewing.
Kimmich is spot on in his description of Conan: it is possibly the most aromatic, fruity, pleasant yeast strain I've encountered (outside of Brett and such.) You can read the full write-up of my first Conan-fermented IPA here, but in short, I can pick out a strong component of Heady Topper in my own beer, despite the fact that the two probably don't use any of the same hop varieties. That peach / apricot character he describes translates into a gently-fruity aroma, and really adds extra punch to the tropical fruit character of certain hops. I believe it also makes for a smoother, richer hop flavor.
Following my IPA, I brewed a strong winter warmer to be enjoyed in December and fermented it on the Conan yeast cake. Though I'm sure it'll fade with time, especially after I oak-age it, the first hydrometer sample from my winter warmer also had a very clear, specific peach aroma. It shocked me how strong it was, especially in a beer with plenty of dark roasty malts. This has given me other ideas: next time I need a low gravity yeast cake for an IPA, I'm going to first brew a sort of adapted cream ale with Conan. With a few choice malts for complexity and a conservative dose of something like Amarillo for flavor, I think you could have a far-above-average "mainstream" beer — a lawnmower beer with unique complexity.
Fortunately, Conan doesn't just taste great — it seems to be an excellent all-around yeast. My IPA, mashed at 152 degrees, hit just shy of 80% attenuation, 1.074 down to 1.015. My winter warmer, fermented on the yeast cake from the IPA, hit 82% attenuation, 1.067 down to 1.012 — though it contained some maple syrup, which is more fermentable than wort. That level of attenuation is great, especially since Conan seems to, paradoxically, somehow, leave a beer with a creamy, full mouthfeel. Everything I've had with Conan has had the impression of a richer, smoother beer than its FG would lead you to expect.
Actual Heady Topper has a final gravity of 1.010 (shockingly low for the flavor profile, in my opinion), and given the 8% ABV, we can surmise that the original gravity is around 1.070. And while I'm not sure how one accounts for mash temp when calculating attenuation, by my estimates, that puts Heady Topper's attenuation around 85%. I'm assuming that must be affected by either a low mash temp (148 degrees F) or some sugar addition, because 85% attenuation for a brewer's strain is pretty nuts.
With more results of Conan-fermented beers appearing online all the time, as well as my own continued experiments, I'm going to pin Conan's apparent attenuation at 80-84% on average. Others have reported highs of 86% attenuation (madness!). The lowest I have seen is 78%, with a high mash temp.
It would seem that the large attenuation range can be explained by different generations of Conan: the yeast mutates quickly, and older generations seem to consistently drop in attenuation.
Highly attenuating yeasts are typically slow to flocculate — too busy eating up extra sugar to drop out — and so far, that seems to be true of Conan as well. It's a pretty stubborn yeast when it comes to dropping out, and my Conan-fermented beers have been hazy even after a couple weeks in the bottle. (This possibly explains the creaminess I get in the mouthfeel of Conan-fermented beers, too). However, as the attenuation drops, the floccuation keeps pace — as you'd expect. My Simcoe Single Hop Pale Ale, which achieved slightly less than 80% attenuation, is also the clearest beer I've fermented with Conan.
In the article linked above, Kimmich alludes to the fact that Conan prefers a certain temp to really draw out those fruity aromatics. I have now fermented beers with Conan on the high-ish side (68-70 F) and the low side (60-62 F). Many brewers, including myself, have been very happy with the results closer to the low side, with Conan starting around 63/4 F and ramping up after a few days. It's not that Conan has produced any unpleasant flavors for me, at any range, but it seems to produce far more aromatic and intense flavors when fermented low. I have let my fermentation temp drop to as low as 60 F with no sign of lag on Conan's part, leading me to believe that it is adapted to ferment at lower temps, anyway. However, mounting evidence from The Alchemist itself suggests that Kimmich ferments Heady Topper somewhere around 68 degrees F, so feel free to push the yeast into the upper 60's without concern. It's a versatile yeast, and not too picky about how you treat it.
Beers I've Brewed with Conan:
Conan IPA (Apollo, Summit, Amarillo, Citra)
Three Trees Winter Warmer
Belma Single Hop IPA
Simcoe Single Hop Pale Ale
Heady Topper Clone