Eisbock is a rare and misunderstood style that is more about process than anything else. It’s related to (and derived from) the doppelbock style, and is created by freezing the beer slightly to concentrate the alcohol and flavors when the frozen water is removed. The science bit here is that alcohol has a lower freezing point than water, so when beer is chilled to slightly below the normal freezing point for water (32 °F/0 °C at sea level), the water portion of beer will begin to freeze first — a process known as freeze distillation or freeze concentration. The slushy, partially frozen water is removed, and the remaining beer has concentrated alcohol and flavor.

An eisbock is not necessarily the biggest or strongest lager, just one that has undergone this freeze distillation process. Traditionally a regional German product, it has been applied to the doppelbock style, so an eisbock is thought of as a lager style. There is no reason why freeze distillation cannot be applied to other base styles, but eisbock is an actual German style not an experimental beer.

This past winter I brewed a doppelbock recipe as a collaboration brew with a local brewpub, and I had to make it as a single-infusion mashed beer, not my traditional double-decocted version. The resulting beer was slightly leaner in mouthfeel, but that is actually an advantage when using it as the base of an eisbock — the technique increases body in the final beer. I think the eisbock method works better when you start with a leaner beer than a huge malt bomb of a lager. It is certainly possible to overdo the flavors.

The style winds up being hard to find in the U.S. commercially because of laws related to concentrating alcohol — it’s basically a form of distillation and technically (read: legally) requires a different (read: more expensive) license. Imported beer may not have the same requirements, and homebrewers certainly have more flexibility in production, which is why I tend to see more of it at homebrew competitions than anywhere else. The Beer Judge Certification Program (BJCP) Style Guidelines categorizes eisbock as Style 9B in the Strong European Beer category, along with doppelbock and Baltic porter.

History

There is a fair amount of lore surrounding the eisbock style. As I say, any explanation that starts with, “as the story goes . . .” usually means “watch out, I’m about to make all this up.” The legend usually involves a hapless brewery apprentice carelessly leaving casks of doppelbock outside during cold weather instead of moving them to the cellar. After discovering that the casks had frozen over night, the brewmaster made the apprentice drink the mistake, which of course led to the apprentice having a grand old time. Of course, no names or breweries are involved, so it’s impossible to verify. I’m not buying it, but this supposedly happened around 1890. 

By whatever (accidental or inspirational) means it was created, it is known that brewers at Kulmbacher Brewery were making this around the start of the 20th century. Founded in 1895 under the name Reichelbräu, it is located in Kulmbach in the Franconian region of northern Bavaria in Germany. Casks of doppelbock were placed outside on cold nights, and the liquid was collected the following morning. The process is now done with mechanical refrigeration, of course, but the beer retains the description “G’frornes” meaning “frozen.”

This 9.2% beer is the origin of the style, but not many breweries make such a specialized product. Niagara Brewing Company in Canada used to make a nice example, although it was only 8% ABV. Some smaller American craft breweries might make it occasionally as a special project, although because it is considered a form of distillation it is usually not well advertised (or possibly not made by traditional means).

As a side note, Schneider makes an eisbock version of their Aventinus weizen-doppelbock that weighs in at 12%. Since this is based on a weizenbock not a doppelbock, I consider this to be a specialty beer in the categorization scheme. This is a modern product dating to 2002, while the original weizenbock was first made in 1907. Although not part of the style for competition purposes, comparing the two versions side-by-side is an interesting experiment (as long as you aren’t driving any time soon).

Sensory Profile

The easiest way of thinking of the style is as a richer, stronger dark bock or doppelbock, but that’s not a complete picture. The freeze concentration process also concentrates flavors (and flaws), producing a darker color and more full-bodied mouthfeel. It isn’t just simply a stronger doppelbock since the process is integral to the style. Some doppelbocks (or other strong lagers) may be stronger than eisbocks. Remember, some commercial examples are under 10% ABV. So, please don’t think of eisbock solely in terms of alcohol.

An eisbock is deep copper to dark brown in color, which is darker than the dark version of most doppelbocks. Yet this color is not derived from roasted malts, so don’t expect any burnt or roast flavors, except perhaps a faint chocolate note. The super malty-rich flavors of Munich-type malts (including dark Munich malts) is prevalent, with their strong Maillard product flavors imparting richness and depth.

An eisbock is a strong lager, so it should have the smooth palate of other German lagers, even if the body is quite full. The alcohol warmth should be noticeable, but hot and harsh edges are still a fault. Concentrated alcohol-related flaws, such as fusels, are a serious fault. The alcohol finish can also help balance the malty richness on the palate. The finish should not be sugary-sweet, sticky, heavy, or cloying, either. 

The aroma is like a dark doppelbock, but more concentrated. Rich bready, toasty malt with light caramel or chocolate notes is common, and a dark fruit character (plums, grapes) is also frequently found in support of the malt. Hops are not found in the aroma or flavor, and just enough bitterness is present to avoid a cloying character. However, the alcohol also can provide some of the counterpoint to the malt richness, not just hop bitterness.

Compared to a doppelbock, an eisbock can have lower carbonation and less of a head. But some examples may have higher carbonation to attempt to offset the increase in body. It should still be a clear beer, although it may be too dark to tell in normal light conditions. The body is fuller, which can make the palate seem somewhat silky. The flavors are more intense and concentrated, but still should be appealing. Discerning tasters should appreciate how a cleanly-fermented beer with concentrated flavors does not become a fault-ridden trainwreck.

Brewing Ingredients and Methods

I won’t really go into depth on brewing an eisbock (doppelbock) since this style is mostly about the concentration process. The base doppelbock grist usually is heavy in the Munich and dark Munich malt, but other malts are common. Pilsner and Vienna malts can be used to cut the richness of the Munich malt. Medium crystal malts can be used to add more depth to the sweetness and bring in some additional dark fruit flavors. Aromatic malt can be used to boost the malt presence. Decoction mashes are traditional but I’ve also made this with an infusion mash, usually with a bump up in the dark Munich malt. Avoid heavily toasted or roasted malts.

Hops are usually just in the bittering, with German noble hops the common choice. A clean bittering hop like Magnum is also a good choice. Low mineral water or water with a light amount of chlorides is fine; anything that isn’t heavy in carbonates and sulfates should work. The yeast should be a clean and neutral lager strain, with low sulfur production. I sometimes use WLP833 (German Bock) yeast in bocks, but here I think it would make the beer too rich and malty. Something a little more attenuative is needed. A normal lager fermentation schedule should be followed, keeping fermentation temperatures cool and lagering for a couple months.

Let the doppelbock finish lagering to clear and clean up any fermentation byproducts. Now you can evaluate it prior to the eisbock process. Do not carbonate the beer yet. Just check that the beer tastes good, doesn’t have any serious flaws, and no longer tastes green. If it does, let it continue to lager. Otherwise, rack it into a purged keg and we can get started.

Before I explain how I concentrate an eisbock, a note about equipment. I normally lager in a keg because I need to use my lagering fridge for this step. I’m using a converted freezer with a temperature controller, so I am able to adjust the temperature accurately. This is important for the process. Don’t use glass fermenters as they can crack or shatter.

With my keg in my temperature-controlled freezer, I set the temperature to around 28 °F (-2 °C) and let the keg begin to freeze. I check it every few hours by gently rocking it, checking for a slushy sound and feeling. We don’t want it to freeze hard, so I don’t recommend sticking it in a snowbank overnight, regardless of folklore. Once at the slushy phase, it’s time to transfer. Don’t let it freeze too much (though if you do, you can always allow it to thaw partially).

There are other ways of doing this. I have heard other brewers let the keg fully freeze, and then thaw the beer, collecting as it melts to reach the desired target volume (and hence, concentration). Others will put the keg just a few degrees below freezing, say 29 °F (-1.5 °C), knowing that the alcohol has a lower freezing point. After a day, remove whatever liquid portion remains, sample, and then lower the temperature another degree if further concentration is desired. Repeat the process until the target volume has been collected. There is some manner of trial-and-error or repeated adjustment in all three methods. Chill out (heh).

I use CO₂ to push the beer into a clean, purged keg, watching the transfer line for signs of cloudiness. I try to push only clear beer. Note that you are basically taking a guess about how much water has been frozen from the beer. We will measure the actual concentration after we are finished.

Once the beer has been transferred, the target keg can be lagered for additional time to condition. I normally check the frozen keg to determine how much water was removed. Let it melt, then measure the volume. I aim for 20% concentration, or about a gallon (3.8 L) of water removed from a 5-gallon (19-L) batch. The target keg can now be carbonated, and enjoyed after it has aged enough to smooth out the alcohol. 

Homebrew Example

My eisbock is really just my normal doppelbock recipe, with the eisbock concentration technique. I know some people say to brew a different type of doppelbock, but I don’t. Or maybe I don’t aim to brew an overly malty doppelbock to start with. Either way, I’m happy with this beer as a doppelbock, but I also think it makes a great eisbock. 

I prefer my doppelbocks to not be super sweet or heavy. It’s still a German lager, after all, and I want to be able to drink a fair amount of it. So, I shoot for a malty palate with rich flavors, but a dry finish. 

I like to use a double decoction with my doppelbock, but, as I mentioned earlier, I did recently make it at a commercial brewery using a single-infusion mash because of the system. So, this recipe reflects that version, except it has my original hop and yeast choices. Really, the hops can be any noble-type variety; in my commercial version, I used Magnum. Just for fun, I tried the Mexican Lager yeast, and found that I really liked the low sulfur, clean and malty palate, and dry finish of it. Any lager yeast with a similar profile is likely to work.

I use the concentration method outlined in the article. Having a temperature controller on a freezer or some other method of accurately controlling temperatures around freezing is the key, as well as having the necessary kegging equipment to conduct the transfers. Pay attention during the freezing process, this should take hours, not days. Maybe smoke a brisket or a pork shoulder while this is going on. You need a similar amount of attention to the process. Give the finished beer additional time to smooth and mellow out, basically lagering it again. Time is your friend here, so be patient and you will be rewarded. 

Eisbock by the Numbers:
OG: 1.078–1.120
FG: 1.020–1.035
SRM: 17–30
IBU: 25–35
ABV: 9–14%

Eisbock

(5 gallons/19 L, all-grain)
OG = 1.081  FG = 1.017
IBU = 21  SRM = 20 ABV = 8.4% (before concentration)

Ingredients
5 lbs. (2.3 kg) Pilsner malt
5 lbs. (2.3 kg) dark Munich malt
4.5 lbs. (2 kg) Munich malt
1 lb. (454 g) Carapils® malt
1 lb. (454 g) CaraMunich III malt
1 lb. (454 g) Caravienne malt
8 oz. (227 g) crystal malt (80 °L)
3.5 AAU Crystal hops (60 min.) (1 oz./28 g at 3.5% alpha acids)
3.5 AAU Tettnang hops (60 min.) (1 oz./28 g at 3.5% alpha acids)
Wyeast 2206 (Bavarian Lager) or White Labs WLP940 (Mexican Lager) yeast

Step by Step
This recipe uses reverse osmosis (RO) water. Adjust all brewing water to a pH of 5.5 using phosphoric acid. Add 1 tsp. of calcium chloride to the mash.

Mash in Pilsner and Munich malts at 152 °F (67 °C) and rest for 60 minutes. Add remaining malts, begin recirculating, and raise mash temperature to 168 °F (76 °C) by direct heat or infusion with boiling water and rest for 15 minutes. Rest at mashout temperature for 20 minutes while recirculating. Sparge slowly with 170 °F (77 °C) water, collecting 6.5 gallons (24.5 L) of wort.

Boil the wort for 90 minutes, adding hops at the times indicated in the recipe.

Chill the wort to 48 °F (9 °C), pitch the yeast, allowing temperature to rise to 50–52 °F (10–11 °C), and ferment until complete. Rack and lager for eight weeks at 32 °F (0 °C).

Rack to a clean keg and move to a temperature-controlled fermentation chamber. Lower the temperature to 28 °F (-2 °C) and check every few hours until the beer sounds slushy when gently shaking the keg. It should be ready within a day or so. Do not allow the keg to completely freeze. The goal is to transfer about 4 gallons (15 L) of beer, leaving 1 gallon (3.8 L) of ice behind.

Prepare a second clean keg. Connect the kegs using a short ‘jumper’ hose between the two beer side posts of each keg. Using a gentle pressure of CO₂, push the concentrated beer from the frozen keg to the fresh keg. Watch the transfer and stop when cloudy particulates are seen in the transfer line. Lager the new keg for up to six months to smooth flavors. 

Force carbonate in the keg. I’m not sure enough viable yeast will be left to bottle condition, which is why I recommend kegging eisbock. More yeast, in addition to priming sugar, would need to be added if you chose to bottle condition.

Eisbock

(5 gallons/19 L, extract only)
OG = 1.081  FG = 1.017
IBU = 21  SRM = 20 ABV = 8.4% (before concentration)

Ingredients
8.25 lbs. (3.7 kg) Munich liquid malt extract 
3 lbs. (1.4 kg) Pilsner liquid malt extract
3.5 AAU Crystal hops (60 min.) (1 oz./28 g at 3.5% alpha acids)
3.5 AAU Tettnang hops (60 min.) (1 oz./28 g at 3.5% alpha acids)
Wyeast 2206 (Bavarian Lager) or White Labs WLP940 (Mexican Lager) yeast

Step by Step
Use 6.5 gallons (24.5 L) of water in the brew kettle; heat to 158 °F (70 °C). 

Turn off the heat. Add the malt extracts and stir thoroughly to dissolve completely. You do not want to feel liquid extract at the bottom of the kettle when stirring with your spoon. Turn the heat back on and bring to a boil. 

Boil the wort for 60 minutes, adding hops at the times indicated.

Follow the remainder of the all-grain recipe instructions.

A bock-strength German wheat beer

While our understanding and categorization of the German wheat beer family has evolved over the years, the acknowledgement of a strong wheat beer called weizenbock has been relatively static. Maybe that is because the prototypical weizenbock, Schneider Aventinus, is truly a world-class beer that is widely available and is well-known. But it could also be because the style guidelines have allowed for a much broader range in this style than in other German wheat beers.

I express German wheat beers as a family of beers because they may cross various style definitions and categories in different style systems. The general use of the term means beer originating in Germany with at least half the grist as wheat malt that use a top-fermenting yeast with a distinctive banana-and-clove profile. Variations by color, strength, and yeast presence in the finished product exist. 

The BJCP (Beer Judge Certification Program) lists weizenbock as Style 10C within Category 10, German Wheat Beer, along with weissbier (hefeweizen) and dunkles weissbier (dunkelweizen). In Germany, you can find lower-alcohol versions (leichtes weizen) as well as filtered versions (kristalweizen); these are not separate BJCP styles, but judges should understand them if they appear in competition. Weizenbock includes variations for both pale (SRM 6–9) and dark (SRM 10–25) versions and it also covers the strength ranges for dunkles bock (1.065–1.074 O.G./16–18 °P) and doppelbock (1.074 O.G./18 °P and higher). Most examples are dark and bock-strength, although the most famous Schneider Aventinus is doppelbock strength.

The German wheat beer family generally is based on the type of yeast used, not just the content of wheat. Just note that outside of this wheat beer family there are several other well-known historical German wheat beers, which include the tart Berliner weisse, the salty-and-tart Gose, the smoked Grodziskie from neighboring Poland, and the sour-and-smoked Lichtenhainer. You can also mention the roggenbier, which is a variation of a dark wheat beer using malted rye. Maybe all of these together could be considered an extended family or perhaps a clan, but all distinct enough to be separate from the German wheat beer family.

Weizenbock’s History

While German wheat beers have a long history, weizenbock is a 20th century invention. As with modern wheat beers, this style traces its history to the famous Schneider brewery, which secured the right for all German brewers to be able to make wheat beers in 1872. Mathilde Schneider is credited with launching Schneider Aventinus, a doppelbock-strength dark wheat beer, in 1907. This product was the motivation for other breweries to develop stronger wheat beers.

Doppelbocks and other strong beers had been made for hundreds of years prior to this introduction, but this was the first documented beer that applied these techniques to wheat beers. Bock-strength beers are by German tradition of at least 16 °P (original gravity 1.065) while doppelbock-strength beers are at least 18 °P (1.074). Note that these definitions are not based on alcohol content; higher final gravities will result in lower-alcohol beers.

Germany also has a tradition of a time for strong beers (starkbierzeit, or literally, strong beer time) in the spring. Think of it like Oktoberfest but half a year offset and focusing on higher-gravity beers. Stronger beers like these are often thought of more as specialty beers than a specific style, so you will see some variety among weizenbocks. As I said, you can find bock-strength versions (like Erdinger Pikantus) and pale versions (like Weihenstephaner Vitus) all grouped together stylistically. 

Wheat beer brewing is more popular in Bavaria than elsewhere in Germany, so you may find weizenbocks from brewers in Munich and elsewhere in Bavaria. Don’t apply too narrow of a style definition and enjoy the special and individual nature of each version. Kind of like drinking in Belgium.

Sensory Profile

Since the style can vary a bit in strength and color, there is also some variation in describing the sensory profile. I like to think about common elements of the style, like the yeast character and overall balance rather than specific variations in the pale and dark versions driven mostly by the malts that provide color. The most important thing to know is that this is a strong and malty German wheat beer and darker versions will have deeper malt flavors. The variation in alcohol strength is of less consideration since they are all fairly strong beers (in the traditional sense), so the bock vs. doppelbock issue should not be given overdue emphasis. Many commercial examples straddle the line between the two strengths, anyway.

Similar to other beers in the German wheat beer family, weizenbocks have a low bitterness and no late-hop flavor or aroma. They use German weizen yeast, which gives a distinctive banana-and-clove profile. The higher gravity can bring in a few esters and some yeast produce interesting lychee fruit notes. However, defects from warm fermentations such as smoky or dirty notes are not welcome. The protein content of wheat generally helps create a thick, long-lasting head and the yeast can provide some haziness. The wheat (and gravity) can give a fuller body, at least medium-full. Any noticeable alcohol should be subtle, not burning. Carbonation is medium to high.

As wheat beers, weizenbocks will have a noticeable wheat malt character, which can be expressed as a bready, grainy, or doughy flavor. Darker versions will have deeper toasted and rich flavors than pale versions (think about the differences between a dunkles bock and a helles bock for a similar comparison) and could have some caramel and chocolate flavors as well. Some of the darker crystal-type malts can add some dark-fruit esters, such as plum, prune, and dark grapes. These malts can produce colors ranging from dark amber to brown in dark versions, and gold to amber in pale versions.

I often describe the mouthfeel of German wheat beers as fluffy or pillowy, which is more of a texture description than an actual body. The higher carbonation tends to lighten the beer, but that is offset somewhat by the stronger malt presence. The lower bitterness can make the beers seem sweet, but they shouldn’t really have a sugary finish. The finish is generally dry and the alcohol can add to this drying sensation.

As with other beers using this type of yeast, it can degrade quickly. Darker malts and higher alcohol can mitigate this somewhat, but wheat beers are prone to going a touch sour over time and losing that fresh malt character rapidly. An interesting effect that is also seen in doppelbocks is that a touch of oxidation tends to enhance some of the Maillard reaction products, giving the impression of a richer maltiness that is not present in fresh examples.

Brewing Ingredients and Methods

Weizenbocks will use malted wheat for at least half the grist, but there are many kinds that can be used depending on the desired color of the beer. I often use dark wheat, caramel wheat, and chocolate wheat in my recipes. But the base of the beer should be traditional malted wheat. If you think about making bock beers, wheat is serving a similar role as Pilsner malt. 

Most examples are dark and bock-strength, although the most famous Schneider Aventinus is doppelbock strength.

As malty bock beers, I like to include some Munich-type malts in the grist. Dark wheat often serves this role, but I might also include some barley-based malts depending on availability, such as dark Munich (Munich II), light Munich (Munich I), and aromatic malts. I use caramel wheat like I would use crystal malts (typically CaraMunich® malts), and I use chocolate wheat like I would use Carafa® Special malts. If you have to substitute, it’s good to know what function the malts are performing in the recipe so you make smart choices.

Decoction mashes are traditional to help break down the wheat malt, which has a high protein content. Single- and double-decoction mashes could be used, although some modern brewers will use step mashes. Rests may vary but often include a protein rest and at least one saccharification rest. One unusual step in many mash schedules is the ferulic acid rest (113 °F/45 °C), which produces ferulic acid that is converted by phenolic off-flavor positive (POF+) yeast to 4-vinyl guaiacol (4VG). 4VG provides the clove-phenol flavor in German wheat beers as all weizen yeast strains are POF+. 

In my experience, weizen strains also produce smoky, burnt flavors when fermented too hot. The weizen yeast strains also produce significant amounts of isoamyl acetate, which gives the banana ester. In many styles, isoamyl acetate is an off-flavor, but in German wheat beers it’s required. Wyeast 3068 and White Labs WLP300 are the most commonly used strains in the U.S., although other similar strains exist. Cooler pitching temperatures (59–62 °F, 15–17 °C) produce cleaner fermentations but still preserve the banana and clove character. Underpitching the yeast and using shallow fermenters are other common pieces of advice for German wheat beers, as they promote ester formation. I don’t tend to underpitch weizenbocks due to their strength, but avoid overpitching.

Hop aroma is almost non-existent in the finished beer profile, so I tend to keep it simple and use a single bittering addition of German noble hops and skip any finishing hops. The water profile is unobtrusive in all German wheat beers. I would use low mineral water with a little bit of calcium chloride, but avoid sulfates.

Homebrew Example

The availability of specialty wheat malts has made brewing this style easier over the years. Weyermann malts are widely available, and are well-suited to this recipe. I’ve also used lessons learned from perfecting my weissbier recipe and applied it to this one. I’ve used this recipe as the base for a blended Smoked Weizenbock that medaled in the National Homebrew Competition multiple times.

The base is German wheat malt, but I also use a large percentage of German Vienna malt to boost the toasty maltiness in the beer. Between these two, we’re looking at about three-fourths of the grist. The remainder is dark wheat malt and aromatic malt (adding malty richness), caramel wheat (a little sweetness, color, and dark fruit flavors), and chocolate wheat malt to adjust the color. It’s not in the recipe, but I normally toss in a pound (0.45 kg) of rice hulls to aid in lautering. It’s cheap insurance against a stuck mash.

I’m using a single decoction mash, which I think improves the mouthfeel of the beer, along with some step mashing. I don’t include a ferulic acid rest because I don’t think this beer needs one, but I might use it in a pale version of this beer. Note that the yeast I’m using is a bit spicier than the traditional Wyeast 3068 yeast, so that’s part of my thinking.

I have used Perle hops here, but any traditional German hop is fine. Hallertauer Herkules has a higher alpha acid, so may be more economical. At 17 IBUs and with no hop flavor or aroma addition, the choice of hops is not that critical as long as it doesn’t add any noticeable character.

My choice here is the White Labs WLP380 (Hefeweizen IV) strain, which is a bit spicier than their WLP300 (Wyeast’s 3068 equivalent) strain. I don’t usually make a starter with this beer since I don’t want to overpitch. I also don’t oxygenate the wort. I tend to ferment my wheat beers on the cool side and the same advice holds here. Many of the tips for working with wheat beer yeast strains seems counterintuitive, but these yeast strains can be picky about their fermenting conditions to produce the desired finished flavor profile. 

I normally recommend that wheat beers be served fresh, but at nearly 8% ABV this one should be matured if it seems like the alcohol is a touch too forward. I think this makes a good cool-weather beer, even if it isn’t “strong beer time.” For me, every time I open a beer, it’s Strong beer time. Yes, I am a dad, and that was a joke.

Weizenbock By The Numbers

OG: 1.064–1.090
FG: 1.015–1.022
SRM: 6–25
IBU: 15–30
ABV: 6.5–9.0%

(5 gallons/19 L, all-grain)
OG = 1.065  FG = 1.015
IBU = 25  SRM = 6  ABV = 6.5%

Ingredients
9 lbs. (4.1 kg) German Vienna malt
4.5 lbs (2 kg) German Pilsner malt
5.2 oz (0.15 kg) Carahell Weyermann
8 AAU Perle hops (70 min.) (1 oz./28 g at 8% alpha acids)
7.2 AAU Perle hops (30 min.) (0.9 oz./26 g at 8% alpha acids)
2 oz. (57 g) Pacific Crest hops (hop stand)
White Labs WLP833 (German Bock Lager)
2/3 cup corn sugar (if priming)

Step by Step
Mill the grains. Dough in using 4.2 gallons (16 L) of water with a target temperature of 133 °F (56 °C). Hold the mash temperature for approximately 10 minutes. Raise the temperature to 147 °F (64°C) and hold it for 30 minutes. Then raise again to 156 °F (67°C). After 20 minutes raise the temperatur to 162 °F (72°C) and hold it for another 20 minutes.

Raise the temperature of the mash to 168 °F (76 °C) and begin sparging with 170 °F (77 °C) water until you collect 6.0 gallons (22.7 L) of wort in the kettle.

The total wort boiling time for this recipe is 70 minutes. At the onset of a full rolling boil, add the first Perle addition. When there are 30 minutes remaining in the boil, add the second Perle addition.

Cool the wort to 172 °F (78 °C) and add the hop stand hops. Start a proper whirlpool and let the hops spin in the wort for 20 minutes. Then transfer the wort to your fermenter and cool it down to 48 °F (9°C). Add the contents of your yeast starter to the chilled wort.

Ferment around 50 °F (10 °C) until the final gravity is reached. Your beer is now ready to rack into a keg or bottles.

Doppelbock is often deemed one of the harder beer styles to brew well. First off, it’s big and bready — the monks brewed it specifically for times of fasting to stave off hunger pangs. But it should not be cloying or overly sweet. This isn’t supposed to be a dessert beer; the finish is meant to be smooth and crisp with toasted cracker malt character, although there are versions that lean more towards dried fruit and some sweetness. Secondly, it’s a lager, which means strict temperature control should be applied to make sure fermentation proceeds slow and steady and brewers need to pitch a lot of yeast.

Doppelbock is a traditional style that dates back hundreds of years in the Bavarian region of Germany. If you trace the roots of doppelbock you’ll find the Paulaner Friars of Munich, a Franciscan order founded by St. Francis of Paula that later became the famous Paulaner brewery. While it was originally brewed in the 1630s to sustain the monks during Lent and Advent, the Paulaner doppelbock Salvator (savior) wasn’t released to the public until 1780. As a tribute, many brewers have stuck to the tradition of naming their doppelbocks with the “–ator” suffix. 

By current German law, doppelbocks must have an original gravity of 18–28 °Plato (1.074–1.112 specific gravity) and an end alcohol content of 7.5–13% ABV. Decoction mashing was historically used for this style, but it is up to the brewer to decide if they want to invest the time into this technique. If you do opt for a decoction mash, I recommend reading advice from Dan Carey of New Glarus Brewing Co., found here: https://byo.com/article/brewing-doppelbock-tips-from-the-pros/

As we turn the corner into cooler and shorter days here in the Northern Hemisphere, four American masters of brewing doppelbocks answered ten questions homebrewers may have when approaching this style. I enlisted the help of Jamil Zainasheff from Heretic Brewing Co. in Fairfield, California; Dave Colt from Sun King Brewing Co. in Indianapolis, Indiana; Andrew Blakeslee from Thomas Hooker Brewing Co. in Bloomfield, Connecticut; and John Trogner from Tröegs Independent Brewing in
Hershey, Pennsylvania. 

So, pull up a seat at the table!

Recipe Design

1. Malts: What recommendation would you give to homebrewers? Any specialty malts you consider key?

Andrew Blakeslee: I believe in an assortment of different specialty malts to layer flavor, but without going overboard. I’ve seen some recipes with only 1–2 specialty malts, and some with over 10. The lower end doesn’t have enough, and the higher end has too many and a lot of them are lost due to low percentages. We use five different specialties in our doppelbock ranging from Munich to chocolate malt. In a doppelbock I consider melanoidin malt to be essential, and a small amount of high-SRM malt with low roastiness for color (I like to use de-husked Carafa® Special III). A small amount of special B malt to enhance the dark fruit character is also a good idea if you want that flavor to stand out.

David Colt: If you are looking to do an authentic/traditional doppelbock-style for your recipe, then we recommend Weyermann malts.  We like to use a 50/50 blend of standard two-row and Weyermann Pilsner.  Some other specialty malts we use are Munich, Vienna, and melanoidin. 

JamiI Zainasheff: I think you only need three malts for the perfect doppelbock: Munich, Pilsner, and Caramunich® (or a similar continental caramel malt). I think the key is using quality continental malts to develop that traditional flavor.  

John Trogner: I’m a huge fan of Weyermann and Durst malts for these styles. Both use a roasting process that can provide a huge range of flavors. I avoid any malt that has a biscuity flavor to them . . . I want bready, straw-flavored malts. 20% Vienna, 20% Munich as a base with a layer of mid and darker caramel and specialty malts. If you want more shelf-stable beer, go lighter on darker caramel malts and melanoidin. I like a very small addition of chocolate and melanoidin malts — less than 1% each. A little goes a long way.

2. Hops: Is there any philosophy that you follow when it comes to hops in the kettle?

JamiI Zainasheff: For doppelbock it’s all about restraint. Often brewers struggle with getting the proper attenuation or have added far too many or too much specialty malt. The sweetness in doppelbock comes more from lower bittering than it does
low attenuation. 

John Trogner: I find hops to be a big controller of the beer’s texture in a style like doppelbock. Personally, I like German Northern Brewer hops, which provide a bright and lemony character earlier in the boil, then Hallertau Tradition for our late addition. We want them to be a background, supporting role in this style, but not to get in the way of the malts here. They’re the real stars of this show.

Andrew Blakeslee: I believe in tradition when it comes to this style, and as such I use traditional hops. We use Hallertau Mittelfrüh exclusively in this recipe, minus a small 60-minute addition of Columbus strictly for IBUs. Doppelbocks are meant to be malt-forward, so the hops are there for balance so it isn’t too sweet on the palate. I recommend 20–30 IBUs total, spread out over additions throughout the boil. We do a 30-minute, 20-minute, and 10-minute schedule.

David Colt: For the bitter addition we use a neutral, high-alpha bittering hop such as Warrior® or Pahto. For the flavor and aroma additions we use Hallertau Mittelfrüh.

3. Yeast: Are there any special considerations when deciding?

JamiI Zainasheff: You can’t make a doppelbock with ale yeast. If you do, it is something else. A strong ale perhaps? You need a German lager strain. My preference is White Labs WLP833 (German Bock Lager) or WLP830 (German Lager). At Heretic, we ended up using WLP830. When Joe Formanek gave me a 50-point score in the American Homebrewer’s Association (AHA) Nationals that was with WLP833. 

David Colt: During Sun King’s history we’ve tried several German lager strains, but we’ve come to prefer Augustiner for this particular style. For homebrewers, Imperial Yeast’s L17 (Harvest) or White Labs WLP860 (Munich Helles), Wyeast 2352 (Munich Lager II), or even SafLager 34/70 would all work well here.

John Trogner: I’m a big fan of Weihenstephan’s 34/70 strain of yeast. It’s widely available to homebrewers in both liquid and dried strains and is an absolute workhorse of a lager yeast. When handled properly it produces very little esters and low sulfur. 

Andrew Blakeslee: Crisp, clean lager yeast is traditional. There are many strains out there that will do this job well; we use White Labs WLP830 (German Lager) yeast. Another yeast I haven’t personally used but think could do well for someone looking for large amounts of dark fruit flavors is Belgian dark ale yeast. This yeast tends to create lots of dark fruit esters, such as fig, plum, etc. that can enhance the malt flavors. This yeast will attenuate much higher than a lager strain however, so some recipe modification would be necessary to maintain an acceptable body/ flavor profile.

4. Water: What brewing salts work with this style and how do you approach residual alkalinity (RA)?

David Colt: Indianapolis has very hard water. Sun King uses a blend of reverse osmosis and municipal water to closely mimic conditions brewers in Bavaria have.

John Trogner: Here at Tröegs we like a very soft water profile to brew Troegenator. We use 90% reverse osmosis water with the remaining 10% being filtered tap water. Once we have that nice clean profile, we add in calcium chloride to achieve roughly 50 ppm calcium and 100 ppm chlorides (give or take some points depending on our tap water profile). We don’t add gypsum for this beer.

Andrew Blakeslee: For a rich, malty brew such as a doppelbock, I would recommend a softer water profile. Ideally, low alkalinity, with calcium at 30–50 ppm, chloride at 30–60 ppm, and sulfate at 20–50 ppm. Add lactic or phosphoric acid as needed for pH of 5.4–5.5 in the mash as well.

JamiI Zainasheff: Don’t overdo it: Everything in moderation. I would definitely keep RA moderate. This isn’t a dark beer, most of the color comes from the caramel malt, which doesn’t have the acidification of roast malt, which is one reason you might go with a higher RA. 

Brew Day

5. How do you approach a big beer like this when it comes to your mash schedule? 

Andrew Blakeslee: We have used a single infusion mash with a low-end mash temperature (150 °F/66 °C). We have a steam jacketed mash tun, so after a 30-minute mash rest at 150 °F (66 °C), we begin to ramp up to mashout at 170 °F (77 °C). A single- or double-decoction mash is something I have wanted to do with this beer and hope to this fall. This will bring more color, flavor, and melanoidins into the beer. A decoction mash will also typically increase mash efficiency, and be slightly more fermentable
(higher attenuation).

David Colt: Most malts are highly modified these days, so we only do a single step infusion mash at 154 °F (68 °C). 

JamiI Zainasheff: We use 152 °F (67 °C) when we want good attenuation. We’ve found that the traditional lower mash temperatures really didn’t result in much lower attenuation and can negatively impact overall extract. The way you get great attenuation is paying attention to your yeast. If you do, you can have great attenuation. The residual longer chain sugars really aren’t very sweet, so as long as you get great attenuation, you will avoid that cloying sweetness problem, regardless of mash temperature. For doppelbock, I think a mash temperature aiming for 154–156 °F (68–69 °C) is ideal. You want some fullness to the beer and a higher mash temperature will help without making it sweet.

John Trogner: While we do perform a decoction mash for our annual Märzen beer, Troegenator is not one we perform a decoction on. Instead we perform a five-step mash that can take upwards of 2.5 hours to finish the mashing process. 

But ultimately it depends a lot more on the malt you are utilizing and your brewing system rather than what works for others. It’s not just about getting conversion complete with an iodine test; it’s about getting maximum conversion for a style like this. Homebrewers could slowly ramp up the mash temperature starting around 140 °F (60 °C) up to mashout temperature or 2–3 key mash rests should provide a nice dry beer as a result. Our research has shown 143.5 °F (62 °C), 149 °F (65 °C), and 154.4 °F (68 °C) are our key rests for a dry beer. 

6. Are you looking for low-, mid-, or high-attenuation from your yeast?

JamiI Zainasheff: It is better to think of mash temperatures and yeast attenuation as two completely separate things. You always want complete attenuation, as much as the yeast will give you under ideal conditions. You don’t want to leave unfermented, worty-tasting beer. So you can mash at whatever temperature you want, just make sure to ferment completely. 

David Colt: Sun King feels like a medium attenuation is perfect for this style of beer. 

John Trogner: We’re after a higher attenuation since the malts should produce plenty of depth and character. 

Andrew Blakeslee: For a doppelbock we look for medium attenuation, around 75% with the lager yeast we use.

7. Any special considerations once the wort is in the kettle?

David Colt: Nothing special, our brewers use a standard 90-minute boil. We prefer to use a direct fire kettle. 

Andrew Blakeslee: An extended boil can increase SRM as well as melanoidins in the beer. A longer boil is also helpful when using Pilsner base malt to reduce dimethyl sulfide (DMS) in the wort. We use a 90-minute boil for this beer, however you can go longer if you’d like and increase to 2–3 hours. If extending the boil, one must account for boil-off reducing volume and increasing starting gravity.

JamiI Zainasheff: I believe in a gentle but obvious 90-minute boil for lagers to reduce DMS precursors. 

John Trogner: DMS needs to be taken seriously with this style and skimping on your boil time may not help your cause. We employ an 85-minute boil but we also have the ability to reduce the pressure within the boil kettle to reduce the boil temperature. I would recommend a gentle boil for homebrewers because we don’t want caramelization reactions to occur in the boil kettle. 

Fermentation and Aging

8. Do you approach fermentation for a big lager like this differently than you would for a lower gravity lager? 

John Trogner: I suggest homebrewers pitch double the amount of yeast than they would in a smaller lager like a Pilsner. The difference between getting a 12 °Plato (1.048 gravity) and a 19 °P (1.079 gravity) wort to ferment dry is big for a lager yeast. We ferment around 52 °F (11 °C) and hold at this temperature for the duration of active fermentation. Previously we fermented a bit colder and then performed a diacetyl rest but found with our 100 BBL fermenter size that our new fermentation schedule works just as well to eliminate diacetyl.

Andrew Blakeslee: We typically will brew one batch day one, and then another batch on day two and put them into a double-batch fermenter. The first batch we pitch slightly warm and with a higher oxygen level. This allows the yeast to propagate for the first 24 hours, and right as they go anaerobic we feed them with more wort, and a small amount of oxygen, and drop to primary fermentation temperature. We also use yeast nutrients to supply the yeast with free amino nitrogen (FAN), zinc, and other important nutrients.

JamiI Zainasheff: We use the same strain (WLP830) as our regular lagers because it is better to pitch enough healthy yeast than it is to get exactly the right strain. For example, if you have some other German lager yeast fermenting already, I would use a pitch from that. If you have some ale yeast or some lager strain that is inappropriate, I would not use that. I would start up a new pitch. So, if you want to use WLP833, then brew a lighter lager with it first to grow it up and then repitch the yeast into the doppelbock. I would never brew a beer like a doppelbock from a new pitch.

David Colt: The only similarity in fermentation between our doppelbock and Pachanga (our Mexican-style lager) is the temperature. Because doppelbocks have such a high gravity, fermentation takes longer and you need to be sure you’re pitching enough yeast and that their vitality is strong. 

9. Do you have a recommended conditioning time for a big beer like this? Do you perform a diacetyl rest?

JamiI Zainasheff: I would start with pitching cold and working upward on temperature. At Heretic, for a normal strength lager we pitch below 50 °F (10 °C). We let the temperature climb unrestrained to 50 °F (10 °C) and then each day we let it rise one or two degrees (0.5–1 °C). After seven days (about eight days total), we are in the mid 60s °F (upper teens °C), and attenuation is complete. We hold it at this warmer temperature and check for diacetyl and acetaldehyde. It always has been clean at this point, but we will usually hold it another week before packaging. We feel like some lagering time improves the beer. For a beer like our doppelbock, most everything is the same, but it takes an extra couple of days to reach terminal gravity.

David Colt: We do not do a target diacetyl rest for any of our beers. We test for it in our lab. I highly recommend taking a small sample to assure that diacetyl is not present before you plan to drastically drop temperatures if a diacetyl rest was not performed.

John Trogner: For homebrewers, I definitely recommend a diacetyl rest because there is nothing worse than a butter-bomb lurking beneath your doppelbock. Our aging period depends largely upon what we are tasting from the beer, but a 6–8 week lagering period around 40 °F (4 °C) is a good benchmark. Also, making sure to dump the yeast/racking off the yeast once active fermentation is complete and some settling has occurred greatly benefits a beer like this. Beef broth components do not help this style at all. 

Another, more advanced technique I think can be hugely beneficial is kräusening. I have found this to add a lot of character to German-style beers when done properly. Finally, we do spund Troegenator. Just like kräusening, I find that if the yeast is healthy and happy at this stage in fermentation, this technique adds lots of complexity and character to the beer compared to non-spunded versions.

Andrew Blakeslee: Once the yeast has attenuated about 60% we let the beer free-rise up to 65 °F (18 °C) for a diacetyl rest. Upon completion of fermentation we taste daily to pass diacetyl sensory, and once it passes we start dropping the temperature 5 degrees (2.5 °C) every 12 hours until we hit 32 °F (0 °C). We usually see diacetyl completely clear after three days. Another option to help with diacetyl is an enzyme called ALDC that prevents the formation of diacetyl by removing its precursor, alpha acetolactate. 

As for the lager period, I would recommend six weeks. That time is obviously dependent on personal taste preference, but four weeks should be the minimum to develop a smooth flavor profile. 

10. Any other things you think are important with this style?

John Trogner: You need to start by picturing the perfect doppelbock beer in your head. Do you envision a drier, crisper version or one that is a more chewy, caramel, raisin rendition? Decide which side of the fence you want to land on. I personally like the dry and crisp version that almost tastes sessionable. That is the flavor profile that Troegenator is based on. As a German brewer once told me, when drinking a great doppelbock, you don’t know you’re drunk until you stand up.

JamiI Zainasheff: It is important to ensure that the beer is clean, not too alcoholic, and attenuates enough to avoid a cloying finish. It is very common to find homebrew versions with fermentation problems. Often the beers did not attenuate completely or they fermented too warm. You don’t want an estery or hot alcohol character. Pitch plenty of clean, healthy yeast and ferment under controlled temperature conditions.

A common flaw is making the beer overly big and alcoholic. Avoid the temptation to go too big on the alcohol. This, like all German beers, should still be easy drinking. Another flaw is making the beer too rich in melanoidin. Too much can make the beer taste meaty or brothy. The cause is often excessive boiling, excessive decoction, or the overuse of specialty grains. 

Andrew Blakeslee: Layers of flavor with none of them overpowering nor underwhelming. Caramel flavors should be present but not over the top. Dark fruit can add a nice complexity to the beer. Color should be a copperish red to brown. A healthy fermentation and extended lagering are also extremely important.

On a separate note, this style of beer also does well with barrel aging in a wide array of vessels. Bourbon-barrel aging, neutral-oak aging, and Port-barrel aging can all increase the depth of character in this style of beer. Bourbon aging will add coffee, toffee, char, and some caramel. Port barrels can increase the dark fruit aspect of the beer and add richness. Neutral oak can add some toasted marshmallow and caramel notes. In general, oak aging will typically create a drier tasting body, despite the final gravity not changing.

David Colt: Relax. Give it time. Enjoy responsibly with some schnitzel!