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Bock and Doppelbock Beer Profiles

Beer styles are not specified and engineered beforehand. They evolve naturally according to local tastes, materials, and resources. Only after the fact are they recognized by brewers, drinkers, and sometimes, governments as official styles. As with any other beer “style”, there can be no hard rules. Brewmasters (and sometimes accountants and marketers) will have their way and name their beers as they please. No style statement can be both completely comprehensive and definitive.

Before continuing the discussion of Bock and Doppelbock profiles, a review of flavor characteristics is appropriate and allows for a more thorough understanding of the subject matter. The concept of a primary, secondary, or tertiary flavor characteristic is from Principles of Brewing Science,22 which is an approximation of work done by Meilgaard and reported in Malting and Brewing Science.23 The idea is that a primary flavor is one that exists in beer at more than twice its sensory threshold. A secondary flavor appears at from one half to two times its threshold, and a tertiary flavor is below one half of the threshold level. Primary flavors are significant contributors to the total character of the beer; secondary flavors contribute background notes; and tertiary flavors do not, of themselves, contribute, although it is possible that there can be perceptible synergistic effects.

Anyone who has tried one of the Munich members of this family knows that beers in the Bock style are malty. They have a strong malt aroma when fresh, are big and chewy, with a sweetness up front in proportion to their rich body. A Helles Bock or Maibock will have more emphasis in the fresh malty flavors, while Dunkles Bocks and Doppelbocks will include some darker caramel, and occasionally smoky or chocolatey flavors thrown in.

In lesser versions, there may be some husky astringency that will mar the smooth, rich maltiness. This may happen when the brewer is working too hard to get the last bit of extract from what is, by its nature, an expensive beer to make. The maltiness is not done to the exclusion of other flavors, however; these beers possess balance.

Balance is a peculiar word in beer tasting, and especially so for Bock, which is inherently at one end of the taste spectrum, heavy in malt.

The key to understanding balance in this context is to realize that even though the hop aromas and flavors will definitely be on the light side, they will still not be found wanting. The hopping rate is crucial! Without the skeleton of hop bitterness to give shape to the beer, it would turn out very flabby and unappetizing indeed. This bitterness is not so much a primary taste characteristic as it is a foil to allow the palate to appreciate the best points of the malt flavor. This sort of balance keeps the palate from quickly growing tired. It shows up greatest in the aftertaste, which in a well-made Bock is long and lingering, and surprisingly dry. This requirement for balance is especially true of the Doppelbocks, without which they would have to be sipped like liqueurs.

Another sensation that appears in Bock beers, of course, is ethanol. It provides a warmth to ward off the winter chill and adds some sweetness. These are primary flavor characteristics. However, these must be in balance with the malt and hop character of the beer. A German brewmaster told me that the secret to producing a fine Doppelbock is that the drinker should be able to appreciate the product as a great beer first, only realizing the strength when getting up from the table. Although the alcohol content of Bock beers has been rising over the last century, it is still unusual for the alcoholic warmth and sweetish flavor to compete with, rather than support the malt and hop flavors.

Furthermore, the harsh aromas and flavors of fusel oils, or higher (longer chained) alcohols, are definitely not appreciated. The only way to rein in the production of higher alcohols from the high gravity worts that Bocks and Doppelbocks require is through careful control of the fermentation process.

This same control, combined with careful attention to preventing oxidation, will also keep down the production of unwanted aldehydes and esters. The cold temperatures will slow the yeast down, forcing it to take its time at the huge banquet that a high gravity wort presents. This will prevent the yeast from running wild through any one particular biochemical pathway where it might otherwise be inclined to indulge because of the overabundance of malt sugars and nutrients.

ALTES BOCK

The prefix Alt means old, old style or old-fashioned, and is used to imply that the item is created in the original or old-time way. Unfortunately, there is not enough detailed information to know that we have really brewed the Salvator of the 1780s, the Ainpoeckisches Pier of 1614, or the Einbecker Bier of the 1300s.

The difficulty in producing old-fashioned beers is that the techniques used are unclear; the actual barley, hops, and wheat strains are unknown and unavailable; the yeasts are unobtainable; and the accompanying microflora indeterminate. Furthermore, peoples’ tastes change. What was “pleasant acidity” in the middle ages may be rather sour today. In total, the task seems pretty daunting.

We know that hard-won brewing gains were considered trade secrets passed on only through apprenticeship, never written down where prying eyes might find them. I have read accounts of the Einbecker brewmaster who moved south to Munich which imply that he was a traitor to his city.

Therefore the style descriptions provided are very rough. I have added question marks to parameters that can only be estimated. All of the numbers are broad ranges, reflecting that none of these measurements were available to brewers in these times, so even if they had wanted to communicate them to others, they would have been unable to do so in an objective fashion.

Since we cannot compare our results directly, technique may not matter much. The grist would have been stone ground, rather coarsely; a Corona-type flour mill set rather loosely may be a good approximation. Sometimes the false bottom in the mash/lauter tun was created by placing straw in the vessel (which would have been constructed of wood) and then adding the mash on top of it. Some older brewing texts suggest a mashing protocol of alternating boiling and blood temperature water, with drainings in between. This is sometimes distinguished with the first one or two runnings being used for the highest quality beer, and subsequent runnings used for one or two lesser beers.19

MITTELALTER EINBECKER BIER

This beer was made from a grist of one-third wheat malt and two-third barley malt, using the palest malts available. Most beer of the time was very dark brown or black, because there was little control over the malting and kilning process. The color here indicated is a bit darker than modern English Pale Ales, which although they are amber in color, got that name because they were the palest beers of their time. I’ve added some more color since we are looking back several more centuries.

The yeast used was wild, but selected; barrels that produced bad beer were destroyed, and good ones reused.13 It was undoubtedly a mixed culture of Saccharomyces cerevisiae and other Saccharomyces species, probably including Brettanomyces species and bacteria. In such circumstances, the yeast would be very under-attenuating by modern standards, and the resulting beer would have much more body and sweetness than a beer of today. (More information on mixed cultures is available in Guinard’s Lambic.)24

Modern mashing and lautering techniques were unknown, so it is likely that a great deal of unreduced starch and protein was carried over into the boil and subsequent fermentation. This would produce higher gravities, but would not add to the sweetness of the beer.

The beer was only produced during the cold part of the year, and was consumed within a few months of the end of fermentation, so some of the more fastidious organisms would not have had a chance to work. This, along with the testimony of Tabernaemontanus, leads to the conclusion that the beer had a noticeable, but not strong, acidity.

Einbeck is situated at the headwaters of the tributaries of the Leine river and surrounded by mountains. Its water is very soft snow melt. This water does not travel very far, and it is all above ground, so we can assume that it would not pick up any mineral hardness.25 Thus the water may be similar in character to that of Pilsen.

Hops are no longer grown in the region, but we can assume that they were low alpha varieties. (They were all low alpha varieties in the past, before modern intensive breeding programs were undertaken). We cannot tell how the hops were handled, or what drying techniques—if any—were used. Because it was not yet understood what part of the hop flower was important to brewing, the female plants would not have been segregated, and the resulting hops would have had an even lower alpha acid rating because of the additional weight of the hop seeds. The effective alpha acid levels must have been very low indeed.

Since Einbeck often falls below freezing during the winter and all beer was brewed from fall through spring, the implication is that the hops would have been relatively fresh. The hopping rate must have been very high to counter the sweetness of the under-attenuated beer, and also to keep the non-Saccharomyces organisms at bay. (This might work out to approximately 4 to 5.5 ounces of a modern 3 percent alpha acid variety per five-gallon batch.)

AINPOECKISCHES PIER

This Bock beer was produced by the Hofbräuhaus München after they obtained the secrets of brewing used in Einbeck.

The beer was made from an all-barley malt mash, as the Reinheitsgebot had already long been the law of the land. To complicate things further, although the brewmaster from the North would have wanted to specify pale malts, that would not have proven feasible. The water in the Isar River that flows through Munich is a chalky green color, and contains a lot of carbonates—at least 150 mg/L, while 50 mg/L is often quoted as an upper limit for mashes of pale malts.22 It would not have been possible to obtain conversion and the relatively clear beer that the Duke required with that combination. The Munich brewers already knew that, and had overcome the problem with the use of acidifying darker malts.

Munich is also not in the center of a hop growing region, although there is a lot of hop cultivation done to the north around the town of Spalt, to the northeast in the Hallertau region just beyond Nürnberg near Hersbruck, and to the west around the town of Tettnang near the Bodensee (Lake Constance). The overland distances involved would have made hops a more precious ingredient, and the prodigious hopping rate would have been cut back. Also the Munich brewmasters knew that a lower rate produced a more balanced beer with their darker malts and reduced the harsh character that the carbonates in the water elicited from the hops.

As this beer was brewed for local, and therefore quicker consumption with less handling involved, there must have been an even smaller chance for the competing organisms to gain a foothold. Thus, this beer was probably less acidic than its northern cousin.

SANKT-VATER-BIER

This beer was originally brewed by the brothers of Saint Francis from the Italian city of Paula for their own consumption during times of fasting. It was intended as a nutrient substitute for solid food. As such, the goal was not high alcohol, at least no higher than necessary to preserve the beer through the fast periods, but instead to carry over as much food value as possible.

This beer did not have a long shelf life. It was prepared for a known, fixed time, and only enough to carry through was made. It was drunk relatively fresh, rather than having a significant lagering period, and had a lower hopping rate. This gave the beer an even sweeter finish, producing a very satiating effect—just the thing required by the monks.

DUNKLES BOCK

As a link to the past of Bock beers, this is the standard-bearer of the style from 1614 into this century. Now, however, it has been mostly supplanted by the Helles varieties and finding a commercial example is increasingly difficult. (Curiously, the Hofbräuhaus München, originator of the style, does not currently produce one, but Einbecker Brauhaus, which originally produced a paler beer, does.) Outside of Germany, this is the predominant style, left over from a time when the style emigrated to foreign lands.

Label is from the collection of Charles Finkel.

The color of a Dunkles Bock is a result of materials and process. The grist used will be of 50 percent or more dunklesmalz, or dark malt. In this context, dark malt is what would be commonly termed Munich malt (7 to 8 °SRM / 14 to 16 °EBC) in the United States. They are called dark malts because they are, naturally enough, darker than pale two-row malt. A small percentage of caramel malt may be added as well (as much as 3 or 4 percent).

The color is increased during a two- or even three-decoction mash, and a long boil. These steps are important to creating an authentic beer. Simple sugars and amino acids combine in a Maillard (or browning) reaction to form melanoidins, which are brown to black pigments. A beer with a high level of melanoidins will have a red-brown to deep-brown color, with garnet highlights.26 Melanoidins also provide the characteristic malty aroma and flavor of these beers.

This is aided by some slight residual dimethyl sulfide (DMS) character, which adds the “lager” flavor and enhances the malt character. DMS levels, which are detectable at 0.03 mg/L levels and are commonly seen in the 0.08 to 0.10 mg/L range, are still never high enough to become independently recognizable as cooked vegetables, creamed corn, or cabbage. They supply a sulfury undertone that makes these beers crisper and more drinkable than comparable gravity barley wines. The longer boil times associated with dunkles beers eliminate more of the potential DMS.

Label is from the collection of Charles Finkel.

The body of a Dunkles Bock is big and bold, yet the beer doesn’t have a corresponding powerful sweetness. Some of its sweetness is due to the ethanol content, which also contributes to the full mouth feel of the beer.27 The high melanoidin content and especially the high percentage of dextrins that result from the grist selection and intensive decoction mashing also add to the rich mouth feel.

Along with these wort production flavors, there are fermentation by-products that affect the flavor and aroma of the beer. The cold temperature fermentations that these beers undergo limit the production of higher alcohols (or fusel oils). Most are restricted to levels well below the taste threshold. In analyses of commercial examples,16,17,28 two exceptions, which may appear at or slightly above the threshold of perception, are isoamyl and phenol alcohols. The former, which can give a solvent or banana character in higher concentrations, can be present in concentrations from one to two times the threshold of 40 mg/L. Phenol alcohols, producing a rose aroma in small concentrations and detectable beginning about 10 mg/L, can appear in concentrations of 12 to 16 mg/L. At these levels, they play the role of secondary flavor constituents and add interesting undertones to the flavor and aroma. They should not be distinctly perceptible.

Similarly, esters should be kept below the sensory threshold. Occasionally, in a commercial beer, one ester or another may actually reach its threshold value. But in such a heartily flavored product, it won’t be noticed independently, and can actually add to the “interest” of the beer. As a rule, esters are to be minimized or avoided by strict control of the fermentation. This is an especially critical point as esters almost invariably rise with higher gravity worts. Staying at or below the “interest” (threshold) level for most esters requires strict attention to and control of the fermentation temperature.

Label is from the collection of Charles Finkel.

Another group of unwanted, potential flavoring components are the vicinal diketones, in particular, diacetyl and 2,3 pentanedione. These compounds can add butter, butterscotch, and honey tones in small quantities (beginning above 0.1 mg/L and 1 mg/L, respectively), and can lead to rancid flavors and aromas in large quantities. Bock beers should not have these flavors. These compounds are formed during the breakdown of pyruvic acid inside the yeast cell, and can leak out into the wort. In a normal fermentation, they will be reabsorbed when the yeast run low on fermentable sugars and then converted to diols which have a very high taste threshold. If the yeast are too flocculant or go dormant before they finish off the sugars in the wort, sometimes fermentation adjustments must be made to avoid leaving these as spillover products. Such adjustments may include inducing a relatively warm period just as the yeast are flocculating out.

Bitterness levels from hops are relatively low. Bitterness obtained from excessive caramelization that might occur either in the boil (from insufficient dilution of extracts or from very hot spots in the kettle) or in a decoction if it is allowed to scorch will add a very unpleasant harshness.

The bitterness plays a background role as a secondary flavor contributor. Typical IBU values range from 17 to 24, not exceeding more than double the threshold value (12 IBU). The bitter character of even the finest noble hops rapidly becomes harsh in the very carbonate water.29 A high hopping rate would compete with the strong malt flavors and produce a muddy result. Also, a high hopping rate would be exaggerated by the carbonate-induced harshness, and overemphasize the conflict in primary flavors.

Relative to pilseners and other continental beer styles, carbonation levels are low in all the dark Bock styles. Both Dunkles Bock and Doppelbock have carbonation rates generally in the range of 2.1 to 2.3 volumes of CO2 (0.41 to 0.45g CO2/100g beer).

HELLES BOCK AND MAIBOCK

Helles Bock is a relatively recent arrival in the Bock family. Although the original Einbecker beer was described as pale, that is relative to other very dark beers of its day. Helles Bock is the result of scientific investigation and technological advances in malting and brewing. These have produced a beer only half as dark as the palest beer of the past, from resources that had previously enforced the exclusive production of dark beers.

Even so the Helles Bocks are designed to walk a fine line between blandness and too much color. The darker colors that come with large quantities of melanoidins are not wanted, but their flavors and aromas are. To achieve this balance, these beers use dunklesmalz, although the quantities employed are much lower than in a Dunkles Bock beer. From a beer that is one third higher in original gravity than a common pilsener, we see at least two to four times as much color. These beers are in the deep gold to light amber range as a result of this compromise in ingredients.

To make up for the lowered melanoidin flavor and aroma, generally a two-decoction mash is used, with shorter boil times. These shorter boil times result in higher DMS levels that emphasize the “lager” character and malt aromas. The DMS levels in a Helles Bock can be two to six times the flavor threshold (30 micrograms/L).

Label is from the collection of Charles Finkel.

Also, more hop bitterness is present than in the Dunkles Bocks to compensate for the missing melanoidins. The water used to make a Helles Bock must be nearly free of carbonates (doing this with waters that are originally strongly imbued with them is one area that required the application of science and technology). This hop bitterness does not take on harsh notes. Instead it is smooth, clean, and refreshing.

Commercial Bock beers tend to have a rather wide range of carbonation: 2.15 to 2.7 volumes of CO2 (0.42 to 0.53g CO2/100g beer). Interestingly, the darker beers tend to be carbonated at the lower end of the scale and the more pale beers at the higher end. But even in those beers that do not follow this general rule, there are few that fall in the range of 2.3 to 2.55 volumes of CO2 (0.45 to 0.50g CO2/100g beer). This “hole” in the carbonation range tends to separate dark from pale beers, but persists even for those that cross over. Generally, Helles Bocks are noticeably more carbonated than the Dunkles Bocks or Doppelbocks.

Maibock is a subtype of the Helles Bocks. It is brewed to the same general specifications as Helles Bock, but with a bit more aging and more hops—up to perhaps 35 IBUs, which would be fairly aggressive in a lower gravity beer. Maibock has a little more color (up to 11 °SRM/25 °EBC) which brings it into the light- to medium-amber range. The hops may even have a cameo appearance in the nose of the beer, but still remain in the background relative to the fresh malty aroma, which is enhanced by the addition of a bit more dark malt. A more assertive version of the Helles Bock, Maibock adds some spice and flair to the reawakening of spring.

Label is from the collection of Charles Finkel.

DOPPELBOCK

Although technically there is no upper bound on the strength of a Doppelbock, and in fact some extra strong varieties like EKU 28 and Kulmbacher Reichelbräu G’frorns (frozen) Eisbock have original gravities well above 1.080 (20 °Plato), almost all “normal” Doppelbocks do appear in this gravity range.

Label is from the collection of Charles Finkel.

Doppelbocks have a color as dark as, or darker than Dunkles Bocks, and for exactly the same reasons. Their mash makeup, carbonate water, triple decoction mashing process, and long boil times all contribute to the dark brown color with deep red highlights. The increase in original gravity emphasizes the color and the other malt-based characteristics.

Bitterness levels from hops are either maintained at or depressed below the low levels already present in Dunkles Bocks. Because the perceived bitterness from the increased melanoidin content to some extent compensates for the lack of hop bitterness, the reduction in hop bitterness may not be as important.

Most Doppelbocks have a low carbonation rate. There are a few exceptions that can be as high as 2.6 volumes of CO2 (0.51g CO2/100g beer), but these are isolated examples outside the usual range of 2.1 to 2.3 volumes of CO2 (0.41 to 0.45g CO2/100g beer).

Doppelbocks originated independently from Dunkles Bocks, but they have grown closer together over time. The comments on other flavor characteristics mentioned above in the section on Dunkles Bocks apply here equally well.

Especially as Helles Bocks have begun to take over the Bock niche, the darker beers have become crowded together. There are now a few pale Doppelbocks appearing on the market. These pale Doppelbocks are more like Dunkles Bocks than Helles Bocks, with only the color change and lower melanoidin content in flavor and aroma to distinguish them. Without the bitterness as a foil, they are sweeter in taste and finish.

OTHER BOCK BEER STYLES

Eisbock: This is a specialty beer produced by the Kulmbacher Reichelbräu brewery in northern Bavaria. Some craft breweries outside the United States have attempted the style occasionally, but to the author’s knowledge, only the Niagara brewery in Canada produces this style regularly. One reason for its rarity may be that extra equipment is needed to produce it. Another, at least within the United States, is that Eisbock production requires a distilling license if the finished beer has an effective gravity higher than its original gravity.

The idea behind Eisbock is that the final product is distilled to some extent by freezing the water and removing the remaining liquid—thereby concentrating all of the flavoring components and the alcohol. By measuring the amount of water removed, the concentration factor can be determined as follows, where Vstart is the volume of the beer before freezing and Vfinal is the volume of the remaining beer after freezing:

Concentration = Vstart / Vfinal

When the original gravity of the beer is multiplied by this factor, it yields as the result an “effective original gravity.” This can then be used to determine the alcohol level of the Eisbock in the usual way.

Because this distillation process concentrates all of the components of the beer, any off-flavors will be concentrated and emphasized. This can make esters particularly noticeable, resulting in very fruity and ale-like flavors. If the original beer had a large concentration of higher alcohols, these will be concentrated and create off-aromas and harsh flavors.

American Bock: A difficulty one finds is that the ground which seemed so familiar previously is now beginning to have new entries from many craft breweries. In the United States, Bock beer used to be synonymous with any dark beer. These beers, sometimes brewed to their own recipes and sometimes merely colored versions of their brewery’s regular beer, are normally brewed from a standard 1.048 (12 °Plato) wort, and end up with a sweet, caramel taste, but little malt aroma or flavor.

However, new interpretations are appearing on the market from innovative craft brewers. Some have taken the existing American style and used quality flavoring and coloring malts to heighten the malt impact. Others have begun with the style parameters of the classic German styles and given them an American twist by using local ingredients like US two-row malt and Pacific Northwest hop strains.

Label is from the collection of Charles Finkel.

Finally, some brewers use the name as a jumping-off point for creating altogether new styles, changing one or more of the parameters well out of the existing categories. They produce very hoppy beers, or perhaps beers made with very clean fermenting ale yeasts. These are new products waiting for public reaction.

Label is from the collection of Charles Finkel.