Experimenting with Imperial Pilsner

It was that extraordinarily exciting time of year again. Average high and low temperatures were dropping daily, some days precipitously. Rain had returned to Portlandia, and the leaves had started to dress up in their fabulous fall colors. It was time for my annual high-gravity batch of homebrew.

In the past, I had brewed American and British barleywines, wee heavy, double IPA, Belgian tripel, weizenbock, and imperial stout, but this time I just didn’t feel the ale vibes I had in previous years. This called for an intense brainstorming session: a growler of homebrew followed by a moderately short nap and a quick run to the can. The answer was simple as could be: brew a strong lager.

But which one? I’d never brewed a lager stronger than a 1.066 (16.1°P) helles bock. Inspiration struck, leaving only a small indentation, and I decided to imperialize some Pilsner. I was so proud of myself for inventing a brand-new style. A style that nobody else had ever come up with. A style that would gain me fame and fortune.

Bubble Busted

Boy oh boy, did I ever get my bubble busted when I searched Google for “imperial Pilsner.” BeerAdvocate listed nearly 400 double or imperial Pilsners brewed in countries from Australia to Uzbekistan. Alcohol levels ranged from 4.2% (not even close to what I’d call imperial) to 11%, and IBU levels varied widely.

Several American breweries have brewed imperial Pilsner. Rogue did a batch exclusively for the 1999 Oregon Brewers Festival, and its namesake collaboration with Iron Chef Masaharu Morimoto comes in a real snazzy bottle. Members of that grand old homebrew club the Maltose Falcons deemed imperial Pilsner special enough to brew it in 2004 to celebrate their 30th anniversary.

Dogfish Head has brewed an imperial Pilsner from time to time, including a collaboration with Italy’s Birra del Borgo called My Antonia. In his book Extreme Brewing, Sam Calagione has an imperial Pilsner recipe that looks pretty good. I admire everything Sam has accomplished and think he’d be a good guy to have a beer or two with, but I must take exception to the statement in Extreme Brewing that dry yeast is not a good option; I use it most of the time with excellent results (check out the recipes that accompany this article).

The day after I brewed a batch of “Emperor” imperial Pilsner I received the November/December 2017 issue of Zymurgy and saw Imperial Pilsner in the Style Spotlight by Amahl Turczyn, so while disappointed that I didn’t invent a brand-new style or start a new trend, I see that I’m on the right track and in pretty good company. Heck, even Mr. Beer has ingredients for a Saazquatch imperial Pilsner.

Imperial Extract Pilsner

To make things a bit easier on my tired old bones, the first recipe I came up with used malt extract. I’ve developed quite a fondness for using Briess Pilsen dry malt extract in European lagers when I don’t feel like brewing all-grain. I also fashioned this recipe to use up a bunch of the large supply of homegrown Sterling hops that were crowding my freezer to nearly overflowing.

I went with double the original gravity of a “normal” Pilsner and four times the IBUs, as I planned to age this one to mellow the bitterness, similarly to what I did with the “Ye Olde” British IPA I brewed for the online extra for the March/April 2018 issue of Zymurgy (“Nostalgia: Exploring 19th Century British Ales“).

Brew day went very well and took way less time than an all-grain day would have, which can be quite important to us old far—…fogies. The water running through my immersion chiller was a bit warmer than I would have liked, so I could only get the wort down to about 66°F (19°C). So, I used a modified warm pitch technique that I came up with several years ago. I pitched the yeast at 3 p.m. and put the fermenter in my 48°F (9°C) “cellar.” By 8 a.m. the next day, the wort had cooled to 52°F (11°C), and I saw the first signs of fermentation a little before noon.

Instead of pitching warm and then waiting for signs of fermentation before chilling to lager fermentation temperature, this method eliminates esters that could be produced when starting a lager fermentation at ale temperature. You have to be really sure to pitch enough yeast in an imperial version of any beer, but especially an imperial lager.

After 21 days of 52° F (11° C) fermentation, I took a gravity reading each day for three days and determined that it was done at 1.012 (3.1°P). I racked the beer to a keg, purged the air, put it in my cooler overnight at 34°F (1°C), and force carbonated the next morning.

I drew a sample from the keg once a month, and after four months the extreme hoppiness had mellowed considerably, and the batch was getting pretty darn good. The darker color—a consequence of making an all-malt imperial beer from extract—made it more a doubled Czech amber lager than the imperial Czech premium pale lager I had originally envisioned. It had a fairly dry finish with a malty, almost sweet edge that really balanced well with the hoppiness. The smooth finish made it hard to believe it was nearly 10% ABV.

Imperial Rice Pilsner

Next up, I went with what I think the big breweries might make if they vacated their “beer that doesn’t offend anyone” comfort zones and went big and bold. After my internet meandering for this article, I concluded that 15 to 20 percent rice would yield a flavorful beer like brewers used to make before Prohibition while avoiding the swill that results from using much larger portions of adjuncts.

Not wanting to complicate my processes by adding a cereal mash, I purchased rice malt from the folks at Gluten Free Home Brewing in Ashland, Ore., who have an excellent array of gluten-free grains like rice, millet, buckwheat, quinoa, and corn for brewers who deal with gluten intolerance issues. The remainder of the recipe came from my local homebrew store, Bader Beer and Wine Supply in Vancouver, Wash.

Along with the rice malt, I received instructions from Gluten Free Home Brewing saying that rice malt should be milled using a wider gap than barley malt. At first, I tried running the rice malt through my mill without adjusting the gap and quickly realized it was a mistake: I had to use so much force that I was afraid of damaging my mill. After opening my mill to its widest gap, the rest of the rice malt went through just fine.

The folks at Eckert Malting and Brewing recommended mashing rice malt at 163°F (72°C) for 90 to 120 minutes, which would have required a separate mash for the rice malt and meant more work and time than I really wanted to spend. So, I took a chance and mashed the rice malt with the Pilsner malt at 156°F (69°C) for 60 minutes, which worked out fine. I got really close to the original and final gravities I was shooting for.

Big brewers often use several different hops in a blend to reduce the influence of seasonal variances in hops from year to year. In keeping with my normal desire to keep things simple, I used a two-hop blend.

I was only able to get the wort in this batch down to 60°F (16° C), so I repeated the “warm pitch” technique that I used on my first batch with similar results. This was my first use of S-23 lager yeast. After two weeks, the gravity was down to 1.020 (5.1°P), and I pulled the fermenter out of the cooler to warm to 66°F (19°C). The final gravity was 1.019 (4.8°P), giving this batch 8.1% ABV.

I was quite pleased with this beer. The color was a bit darker than a normal-strength Pilsner would have been, but the moderate bitterness and light crisp edge from the rice malt made it deceptively easy to drink. You don’t realize just how strong it is until you try to stand up. I also didn’t experience any of the fruity flavors that some brewers have reported with S-23.

Imperial Maize Pilsner

I was in the brewing zone and went ahead with a third recipe that included some ingredients I’d never used before: flaked corn, Horizon hops, and Smaragd hops. I also used my favorite dry lager yeast, W-34/70.

You know what it feels like when you’re on a roll? Nothing but 7s and 11s? I was on a brewing roll. I hit my mash temperature target within 1°F (0.6°C), my batch sparge left me with the exact preboil volume I wanted, and the boil yielded 5.25 gallons (21.8 L) in the fermenter. My “warm pitch” technique worked perfectly again; I had signs of fermentation within 24 hours and I hit my projected final gravity within two weeks.

After 21 days, I bottled with the intent of lagering in the bottle, and I had one of the smoothest bottling days ever. The beer was nicely malty with just a touch of corn sweetness. And the hoppiness was just the perfect amount to balance it all out.

Turns out it’s not all that hard to brew imperial Pilsner: proper sanitation, recipe planning, plenty of yeast, and patience will give you a darn good batch of beer. And if I can do it, anyone can, so don’t be afraid to pump up the volume when brewing a lager. Imperial helles, super schwarz, double Dortmunder, massive Märzen, whatever strikes your fancy. Go big or go home!