Brewing Maibock: Tips from the Pros

Brewing Maibock

Most people love May for its warm weather and feeling of impending summer. The Germans love it so much that they even named a beer style after it: Maibock, which means “May bock.”

Bock beers should start at around 1.064 OG. Maibock is traditionally light-colored, malty and lightly hopped for medium bitterness. It’s fermented with a lager yeast, at temperatures between 45° to 50° F. This month’s pros suggest 4 to 8 weeks of lagering at near-freezing temperatures.

Maibock is potent, but it’s also fragile. It’s a big beer, yet it’s a lager, which makes it vulnerable to temperature spikes. This makes Maibock a great experiment for the advanced brewer, but even beginners will benefit from this month’s pro tips.

Brewer: Bryan Pearson of The Church Brew Works in Pittsburgh, Pennsylvania. After college (with a degree in physics and a minor in math), Bryan took a brewing job at the Village Brewery in Houston, Texas. He has attended numerous brewing seminars and has been a  brewer at The Church Brew Works  for almost five years.

There are two keys to a great Maibock. First, ferment it nice and slow, at cold temperatures. Second, age it. These steps make for a nice, clean beer.

Yeast selection is very important. It should be something clean and German. I use Bohemian Lager (Wyeast 2124) but you could get away with the Munich Lager (2308) or Bavarian Lager (2206). My yeast has moderate flocculation. It ferments nice and cool at 47° F. It also leaves a nice, malty flavor, and is very clean when fermented and stored at the right temperatures.

Maibock will be a very big beer that’s complex, but weighted toward the malt. I prefer to use imported Belgian malts from De Wolf-Cosyns, with a malt profile that includes pilsen, Munich, aromatic, carapils and wheat malts. I have been pleased with the performance of these Belgian malts; the specialty malts work especially well for us.

The Munich malt adds to the body and maltiness, plus lends color, while the aromatic malt gives a bread-like character that accentuates the malt character of the beer. I add the carapils for body, and use a modest amount of wheat to enhance head retention.

We then do a double-decoction mash. We mash-in at 122° F for 5 minutes, using this as a protein rest. Then we pump away one third of the mash to the kettle, leaving behind the other two-thirds. We then slowly raise the temperature, holding it at 144°, and then 152° F, for a few minutes each time. Then we bring it to a vigorous boil for several minutes.

We pump that portion of the mash back into the other, letting it mix briefly. Because of the temperature of the boiled mash, the temperature rises to 144° F, giving us the first starch conversion.

Then we pump away one-third of the mash again, raising the temperature to 152° F and then to a boil. We pump it back, mix it up, and let the mash bed set up with the whole mash now at a temperature of 152° F. The mash continues until starch conversion, and we mash-out at 170° F. I really think that decoction is worthwhile. I believe it increases the complexity of the malt character and improves malt efficiency.

We shoot for 28 IBUs, using Perle for bittering hops and boiling them for 90 minutes. Ten minutes before the end of the boil, we add Tettnanger for flavor and aroma.

After the boil, we drop the temperature of the wort to 54° F and pitch the yeast. I double the yeast for a heavy beer like this, using about 25 to 30 million yeast cells per mL for the Maibock. After the yeast gets a good start, I drop the temperature to 47° F. It should ferment out in about one week.

Near the end of fermentation, I start a temperature rise back to 54° F for a diacetyl rest. This makes the yeast more active, ensures a more complete fermentation and mops up the diacetyl. If you don’t do it, you risk a sweeter beer. Let your Maibock age a minimum of two months at, or just above, freezing.

Brewer: Lochlann Kehoe of Baltimore Brewing Company in Baltimore, Maryland. Lochlann started at the BBC after college and has worked there for three years.

Our Maibock is made with 100 percent pale malt. I find it crisp and refreshing. We add hops three times during the boil. The first addition is Nugget, followed by a mixture of Nugget and Hallertauer (at a ratio of two parts Nugget, one part Hallertauer). We then finish with Hallertauer, which gives us a hint of a flowery nose.

The finished beer is not very bitter. It’s maybe one-quarter the bitterness of a pilsner. The IBUs should be around 30 for a Maibock.

Since it’s a bock, you definitely want to taste the malt in the final brew. We get a good malt flavor by using domestic malt. The hop aroma and taste will come out mildly on the palate, and you should never be able to taste the alcohol when you drink the beer. Typically, a Maibock should be around 7 percent by volume. You can start tasting alcohol at concentrations between 8 to 9 percent by volume.

For the Maibock, we do step-mashes rather than a regular infusion mash. We think it improves the flavor and improves efficiency. There are four temperature rests along the way. Each is for 30 minutes. We start at 98.6° F, raise to 122° F, then between 144° to 149° F and then 158° F. Then we mash out at 170° F.

Sparge water should be at 171° F, since this is best for sugar extraction. It also knocks out the enzymes that were at work in the mash converting starches to sugar.

Since this is a lager, you should ferment around 48° to 50° F. As a homebrewer, my lagers always turned out awful because I couldn’t control the temperatures. If the beer gets too warm, you get off flavors. If it’s too cold, you knock out the yeast. And if it’s too cold at the end of fermentation, you won’t get any diacetyl absorption.

Temperature is definitely one of the bigger challenges.

We don’t do a diacetyl rest. We “trust the yeast,” which means that we believe that it will do its job all the way through without us influencing the temperatures.

Age this beer for four weeks at least. We drop the temperature to just below freezing (31° F). After a month, it’s a nice, crisp beer.

Issue: April 2001