Kellerbier is a beer that merges the best of British cask ale with German malts and hops in a unique lager style. It has an atypical flavor profile that, depending on your finishing steps, can represent itself as a kind of German ESB or a Continental IPA. Because it’s a relatively new style to the U.S. craft and homebrewing market, you might have trouble finding commercial or homebrewed versions to compare yours to, but this version should get you pretty close to the mark!
There’s some dispute over whether Kellerbier is an actual style of beer or a production/serving method. Strictly speaking, Kellerbiers are cold-fermented (in cellars), bottom-fermenting beers that are generally served young and unfiltered. Many are also served with low levels of residual CO2, having been matured in vented casks that retain very little carbonation in the beer. For our purposes, though, you can refer to the “Amber Kellerbier” descriptions in the 2015 BJCP guidelines for a sense of the target flavor profile. It’s essentially an amber lager that differs from Oktoberfest in the relative intensity of its hops character across all fronts—bittering, flavor, and aroma. It is also unique in that a touch of acetaldehyde and other “green” beer flavors are not necessarily considered a fault (though we’re going to avoid them here).
A strict reading of the guidelines also suggests that the beer should have moderate carbonation, but we’re going to deviate from that (in the interest of historic authenticity, and, I think, enjoyability). If you plan to enter this beer in competition, you’ll want to carbonate to a full 2.5 volumes, at least for the bottles to be entered!
There’s a trick to this style in that you want a rich, obvious malt-forward character and a nice amber color—but you don’t want any caramel or roasty flavors. Dialing in the grist is essential (though it should be noted that this whole recipe/process is a bit challenging—there won’t be any “easy” parts of this journey!). In order to get a nice, bready, non-caramel malt character, I use Vienna and Pilsner as a base, in a 2:1 ratio. Any more than that, and the beer may come across as being too apparently sweet, even though it will still ferment out fully. But to deepen the color (without adding roast) and the flavor (without adding caramel) I add trace amounts of Carafa II and Melanoidin Malt—3 ounces (85 g) of each. That should get you to a starting gravity of about 1.050.
You also need to get aggressive with your hops, at least compared to other European lagers. The goal is about 35 IBUs, along with medium-high levels of hops flavor and aroma. To get there, I use a 1:1 blend of Hallertau (4.5% AA) and Northern Brewer (8% AA), 3 ounces (85 g) total, with 1 oz (28 g) at 60 minutes, 1 oz (28 g) at 30 minutes, and 1 oz (28 g) at 10 minutes. I’ve found that the combination of German noble hops results in a healthy dose of floral hops flavor while the Northern Brewer adds a wild, dry-bark note. In amber beers, it imparts an autumnal character that is hard to beat!
For yeast, you have a few options. Those who are expecting my old standby Wyeast 1007 German Ale are going to be disappointed; it’s a great yeast, but for this beer I like a true lager strain to avoid the impression of sweetness that esters can impart, so it’s Wyeast 2206 Bavarian Lager. If you’re going to go ale yeast, though, this is one time when I recommend the cleanest one you can find: White Labs WLP001 California Ale yeast—it’s an acceptable alternative, though I still think the lager yeast is the way to go.
Mash as usual at 152°F (67°C), and boil away—those who insist on doing so may boil for 90 minutes, but be sure to adjust your recipe to account for the higher level of evaporation (for my part, I’ve never done anything but 60-minute boils and have never had any issues with DMS). Pay particular attention to your late hops timing—you want to ensure a noticeable level of hops flavor and aroma, so if you’ll be doing a whirlpool, be sure to factor that time in. You want 30 minutes of contact time on the flavor hops and 10 on the aroma hops.
In fermentation, pitch and hold at a steady 50°F (10°C) for the first 5 days, then start increasing the temperature. Once you’ve reached terminal gravity (about 1.011), get it packaged up and ready to drink! Ordinarily, you’d let it rest for a while to allow the yeast to clean up and clear out, but for Kellerbier you want that bit of yeasty breadiness and “young” flavor. And if you’ve pitched a healthy and properly sized slug of yeast, there should be only a hint of that “green” beer flavor (any more than that and…well, it just starts to taste like a fault to my palate, but feel free to give it a try!).
I serve this beer at a British-cask-like-just-less-than-one volume of CO2. If you can serve it in a cask and off a genuine hand pump, then all the better. The result should be an eminently drinkable amber lager that has a soft, rounded mouthfeel and a ton of light-malt flavor, accentuated by floral-spicy hops flavor and aroma. It’s a unique beer, and I highly recommend trying it this way at least once!
If you’re more conventional, though, you can package as normal and carbonate to about 2 volumes of CO2 (any more than that wrecks the delicate flavors, in my opinion), and doing so gives it a flavor akin to a German version of English IPA. Still interesting, but not quite distinct enough from a traditional altbier to make it worth your while, though. If you want to make a proper German IPA, double the hopping all around with this same grist, and you’ll be on the right track!
Kellerbier (pale or amber, but I think you’ll enjoy this amber version more, especially as we move into fall!) is a fun beer to add to your repertoire, and also makes for a very good “transition” beer for your “heavy” macro drinking friends and family. Go the low/no-carbonation route and see what you think—you may never go back to full carbonation again.