The Dortmund Question

My last post was ostensibly about how Bohemian brewers felt about North German breweries co-opting the name "pilsener" to describe their pale lagers. The article from Der Böhmischer Bierbrauer that I reference in the post includes several references to quotes by Professor Wilhelm Windisch, one time chief of the VLB in Berlin, where he praises the qualities of Dortmund beer, whilst musing why German brewers felt it necessary to co-opt a foreign brew.

We all kind of know the general outline of history when it comes to pale lager, Josef Groll creates Pilsner Urquell in 1842, which is just a hair paler than Anton Dreher's Vienna Lager, and thus kicks off a pan-continental craze for pale bottom fermented beers. By the end of the 19th century, the list of "styles" that have come about as a result of Groll's introduction of English malting technology to Central Europe included Helles, Biere d'Alsace, North German Pilsner, Polish Mocne, and of course Dortmunder. All of the styles followed the same basic template, pale malt and the local hops, from Strisselspalt in Alsace, though Hallertau and Tettnang in Germany, up to Poland's Lublin.

In our hop centric minds in the early 21st century, we make the assumption that the main driver of differentiation in all these beers was the presence of local hops, relegating malt to essentially the role of hop delivery system. However the role of malt in the development of beer styles seems to get somewhat overlooked, as if all pale central European beers can be brewed with pilsner malt and whatever hops are appropriate. Historically that seems not to have been the case.

I wish I could remember where I first came across the term "Dortmunder malt" but alas the old grey matter is, well, getting older. However, I did find, not in the newspaper archives of the Austrian National Library I am sure you are relieved to hear, a book called the "Handbuch der Enzymologie, Vol II" on Google Books. On page 1236 of the book there is a fascinating breakdown of the different base malts in use in Germany at the time, I believe the book dates from the 1940s rather than the 1545 Google claims. In this section we get a description of the "dark" Munich malt, the "pale" Bohemian and Dortmunder malts, and the "golden" Vienna malt that is a middle ground between the others.

According to the writer, the fact that Bohemian and Dortmunder malts are pale is the only thing they have in common. He goes on to explain how Pilsner malt is modified "just enough" (major shout here to Andreas Krennmair for helping me with the translation of "Auflösung" meaning "modification" in a malting context) while Dortmunder malt is fully modified just like Bavarian malts. As you probably know, modification with regards to malt refers to:

"the extent to which the endosperm breaks down...releasing nutrients for yeast growth and making the starch available for enzyme degradation during mashing"*

In addition to be more fully modified that Bohemian malt, Dortmunder is also to be treated more gently that Pilsner malt, with the kilning process not reaching temperatures of more than 75°C/167°F. The writer describes the kilning process of Pilsner malt as being "pre-drying at 35-40°, rising to 55° until the water content reaches 8%, then kilning up to 100°", kilning also only takes 3 to 4 hours.

Apparently if you subject Dortmund malt to the same process it would become far too dark. Essentially Dortmunder malt needs to be carefully tended when compared to Pilsner malt so as to stay pale whilst achieving a full modification like Munich malt.

It would appear then that, at least in the 1940s, Dortmunder beer was brewed using specifically Dortmunder malt rather than the modern approach where "Pilsner" malt is the base. However, as early as 1913 Der Böhmische Bierbrauer was referring to "so-called" Dortmunder malt as a "minor type" of base malt, whilst describing it as "lightly kilned". It would seem that it was the use of Dortmunder malt that prevented the style from becoming the dominant German beer.

In an article from 1899 in the brewing journal "Gambrinus Brauerei- und Hopfen- Zeitung", the writer discusses why people were moving away from Dortmunder towards Bohemian beers. The writer confirms again that Dortmunder malt is kilned at low temperatures and thus very pale. He goes on to state that such low kilned malt has an "empty taste", and such a paucity of flavour causes the breweries to stick to brewing a 14° beer, which the writer defines as being "ein alkoholreiches Bier" - an alcohol rich beer - inferring then that Dortmunder was strong because that was it's main redeeming feature. The writer finishes his section on Dortmunder beer by comparing the beer with the Bohemian 10° beers that were "doing so well on the market" by stating they are "good beers, that hold their foam well, and don't taste empty at all".

At the end of the day, the average consumer wanted something that was flavourful, looked good, and wasn't "alkoholreiches", and thus Dortmunder was relegated to an also ran of the pale lager world, with Dortmunder malt eventually dropping out of production altogether it would seem.

* quote from "The Brewer's Handbook" by Ted Goldammer - https://www.beer-brewing.com/beer_brewing/beer_brewing_barley_malts/malt_modification.htm