Category Archives: Brewing

19th Century Brewing Methods in Germany and Austria

Only the other day, I stumbled upon a book called “The Art of Brewing“, written by one David Booth, published in 1834. It has a whole section of brewing in foreign countries, discussing differences in brewing between Munich, Prague, Vienna, and other cities. The basis for this section is credited to two unnamed guys, can you guess who?

For the greater portion of ” the Brewing in Foreign Countries,” I am indebted to the manuscript and oral communications of two German Brewers (from Vienna and Munich), who have been, and now are, visiting the principal towns of Europe, for the laudable purpose of acquiring information concerning their business.

Yep, that sounds very much like Gregor Sedlmayr and Anton Dreher.

I also found another book, “Vollständige Braukunde” by Johann C. Leuchs,  that discusses the brewing methods of various German cities. In this article, I will try to summarize and discuss different German brewing techniques from the 19th century, and how they would be seen from a modern (home)brewer’s point of view.

Munich

For the mash, a mash tun made out of copper, with a false bottom, and a second, smaller copper, were used. The second copper was used for boiling the mash. The standard recipe is described to be 8 quarters of malt and 60 pounds of best Bavarian or Bohemian hops to produce 27 barrels of keeping beer. Calculating what the outcome of that would be, that would be a beer with about 6 to 7.5 % ABV, with probably 35 to 50 IBU. It does mention the Munich beer as keeping beer, meaning it was matured, or lagered, for a relatively long time.

The coarsely ground malt is doughed in, while the small copper is used to bring liquor to a boil. The boiling liquor is then added to the mash, to result in a 40 °C mash. Then a decoction is drawn, and brought to a boil. The author mentions a thick froth that is beaten down back into the mash. I assume this is hot break, and nowadays you would rather skim the scum instead of beating it back into the mash.

The first boil takes about an hour, where it gets a darker colour, until it is put back into the mash, to raise the temperature to 55 °C. Immediately, another decoction is drawn, but only boiled for 30 minutes, and then put back, with a resulting temperature of 67 °C. A third, thin decoction is then drawn, both taken from the top and taken from the tap (the mash tun has a false bottom, after all). Then it is boiled for 15 minutes, and put back, to reach a temperature of 75 °C. That whole procedure takes about 5 hours.

After that, the wort is drawn off. Hops are added while the first runnings are still drawn off, so this constitutes a first wort hopping. The overall boil lasts 2.5 to 3 hours. Fermentation is bottom-fermenting, as expected. What’s interesting is that after primary fermentation, the young beer is drawn into casks. A batch is spread out over lots of casks, though, so it takes about ten batches to properly fill all the casks. I presume this is to blend all the batches and to end up with a very consistent product over all casks even when the individual batches differ. Lagering period in the cellar is mentioned as lasting eight to ten months. That is indeed a keeping beer.

Beer brewed for the winter differs from this, as less hops are used, more wort is drawn off, and it’s boiled for a shorter period of time. There is very little maturation, and secondary fermentation for carbonation is initiated with Kräusen, and essentially happens in the publican’s cellar. This very much sounds like a running beer. Comparing with modern drinking habits, this is very counter-intuitive, as you’d expect the lighter beer to be brewed for the summer as a refresher, and the bigger beer to be made as a warming, boozy drink.

Augsburg

Apparently, the brewing methods in Augsburg were quite different from the rest of Bavaria. It starts with the malt: it is ground finely. The boiled hops of the previous batch are put on the false bottom prior to putting malt and then cold liquor over it. This is left for six hours. Boiling liquor is then added, and mashed for half an hour, and then more hot liquor is added, to bring it to 60 °C. This is then left for two hours. Sweet wort is then drawn off and put into the cooler. More hot liquor is added, and mashed for half an hour, with the resulting temperature being 67 °C. Then “all the goods” (I presume this means all hard matter) are put into the copper with hot liquor, and boiled for 45 minutes, then put back into the thin mash. The resulting mash is then at 86 °C. After some time, the cooled wort is put into the copper, the wort from the mash is also drawn off, hops are added, and the whole thing is boiled for two hours.

Fermentation is bottom-fermenting, and the beer is ready after about 2 months of maturation. Usually though, it is kept in large vats for a year to 1.5 years.

According to “Vollständige Braukunde”, beer brewed like that requires more cleanliness than the Munich approach, but has a higher yield and produces a milder beer.

Overall, a rather weird method in today’s standards. It seems like an infusion mash in the beginning, but with a final decoction, which would extract complex carbon hydrates, but leave the mash at temperatures where all amylases would have already been denatured, and no enzymes would be left to convert the starches into more simple sugars. Did the Augsburgers like their Blausud? (a Blausud is when a wort sample, mixed with an iodine solution, turns dark blue: it is an indicator that there’s still unconverted starches in the wort)

Prague

Prague’s brewing methods are described as similar to Munich, but with a fermentation “of the opposite kind”, which I assume means that in the 1830’s, Prague was still brewing with top-fermenting yeast.

Dough in starts at 46 to 50 °C, with an initial rest of nearly an hour. During that mash, more hot water is added to reach 59 to 63 °C. Then a decoction is drawn, brought to a brief boil, and then put back to get up to 67 to 68 °C. Then another rest of an hour follows. Wort is then run off, a Vorlauf if you will, with the express purpose to get rid of any grains underneath the false bottom. This wort is brought to a boil, and put back, to bring the temperature of the mash to about 84 °C. It is also emphasized that the grains must not be disturbed. Then a small portion of the wort drawn before is brought to a boil together with the hops, and the hops are taken out after 45 minutes. In total, the wort seems to get drawn off in batches and boiled, with the hops getting reused. A sparge is done, and the runnings are boiled with the hops from the previous boils.

Fermentation is done at 20 to 22 °C, so obviously top-fermenting. Maturation then happens in ice-cooled vaults for four to six weeks, and is served directly out of that cold environment. Yep, ice-cold beer.

Anyway, what we can see here is that the Munich style of mashing is a triple decoction, while Prague employed a double decoction.

Vienna

The crushed malt is doughed in with cold water, and mashed for two to four hours. Then cold wort is drawn off, and is brought to a boil together with liquor, boiling for 45 minutes. The froth on the top is skimmed off. It is then put back onto the malt, with a resulting temperature of 40 °C. Now this seems quite odd to me, as it would mean that a lot of the enzymes in the wort would be denatured quite early on.

Then something truly odd is done: wort is drawn off, and pumped back onto the mash. This is done for over an hour. A certain amount is kept in the copper, and again brought to a boil, but as soon as it starts boiling, it is added back to the rest of the mash, to increase temperature to 57 °C. Then more wort is drawn into the copper, again brought to a boil, boiled for 30 minutes, then put back into the mash. This is now left for 30 minutes at 72 °C. And then more wort is drawn off, again brought to a boil of 45 minutes, put back into the wort, and left for another hour at 82 °C.

Then wort is drawn off once more, and hops are added. When all the wort has been drawn off, the grains are loosened, and water of 56 °C is sprinkled onto it. The wort is boiled for 75 minutes, and some of it is put into the cooler. Then the second runnings are drawn into the copper, and boiled for another 90 minutes.

Then the wort is cooled to about 30 °C, and yeast is added. That’s a crazy pitching temperature. Fermentation is vigorous, and the young beer that is thrown out during the fermentation is collected and fermented in a separate vessel. This sound vaguely like the idea of a Burton Union, although with a separate vessel instead of recirculation. Shortly after fermentation has finished and the yeast has settled, casks of the young beer are sent out to the publicans. This all happens within 3 days.

So, in total, quite a strange process. Kinda like a decoction, except only thin decoctions are drawn. I wonder what prevented this from resulting in a Blausud, as well.

Berlin

This gets interesting now. Berliner Weisse. “The Art of Brewing” describes it as a beer made from 5 parts of wheat malt and 1 part of barley malt. That’s quite different from the 2:1 or 1:1 recipes that are listed in other old publications. “Vollständige Braukunde” mentions 20 parts of barley malt, 10 parts of wheat malt, and 2 parts of oat malt.

The finely ground malt is doughed in, and hot liquor is added to bring the temperature up 52 °C. This is left for an hour. Then wort is drawn off, and boiled with hops for 15 minutes. A thin decoction is drawn to interrupt the boil, and when this has reached 93 °C, it is put back into the mash, and left for 30 minutes, with a resulting temperature of 67 °C. Then another thin decoction is drawn, heated up to 96 °C, then both the mash and the decoction are put into the “tap-tun”, what sounds like a lautering vessel with a false bottom which is covered with straw (some sources say straw used in lautering was previously boiled in water). The resulting temperature in this tun is 75 °C. The wort is then drawn off, very slowly, though, and hot liquor is used for sparging. The overall lauter and sparge takes 7 hours, to produce a very clear wort. The wort is then put into the fermenting vessel, where yeast is added. Fermentation quickly begins, and the beer gets already shipped out to the publicans at this early stage.

In “Art of Brewing”, the author mentions that brewers thus have no yeast, and must buy it back from the publicans. To keep their yeast strains reasonably clean, they preferably buy from publicans that deal with other breweries than their own. The publicans also take care of bottling and storing the beer until it’s drinkable, which is usually after 14 days.

In total, this is quite the interesting process, as it does a kind of decoction, with the hop boil during the mash, and no further boil. Berliner Weisse is often described as a no-boil recipe, and people often ask themselves how the hops are added to it if there is no boil: directly during the mash. This way, the amount of isomerization of the alpha acids is easily to control, which is usually not the case if you added hops to a thicker mash that would undergo several decoctions.

Summary

In this article, I tried to summarize descriptions of different brewing techniques in German and Austrian cities at that time, in particular Munich, Augsburg, Prague, Vienna, and Berlin. It is interesting to see how the approaches completely differ, in particular the amount of decoctions that are drawn, what kind of decoctions are drawn, what is boiled for how long and in what order, and what temperatures are kept. With today’s knowledge and understanding of brewing and the microbiology behind it, it is fascinating to see what would be considered good practice nowadays, and what wouldn’t. The Munich triple decoction is a well-researched and well-documented method, as is the Prague double decoction. You would find descriptions of these in most modern brewing literature. The other methods, not so much. There, we find temperatures that would extract more tannins, or early thin decoctions that would denature lots of crucial enzymes early on in the brewing process. I seriously wonder how these brews went fine, and whether they produced Blausude.

DMS and Boil Time

After writing about the sources of DMS in beer a few days ago, I stumbled upon another quite interesting paper from 1978 that discusses the influence of boil time on the amount of DMS in beer, titled “Control of the Dimethylsulphide Content of Beer by Regulation of the Copper Boil”.

In this paper, the authors put together two different lager malt blends. LMB 1 was designed in such a way that it was kilned at 65 °C, so that it would only contain inactive DMS precursor (see the previous article about active and inactive DMS precursors). LMB 2 on the other hand for kilned at 70 °C and later at 90 °C, so that it would contain substantional amounts of active DMS precursor. With both malt blends, worts of OG 1.037 (9.25 °P) were produced using a single-step infusion mash at 65 °C. The worts were boiled for different times (from 15 minutes up to 2 hours). Each of the worts were split, and fermented with different yeast strains, NCYC 240 and NCYC 1324. The two different yeast strains differ in the amount of DMS they produce: NCYC 240 produces a high amount, while NCYC 1324 produces a low amount.

What was noticeable in the results from the different boil times alone is that there a strong correlation of boil time with decreased amounts of DMS and DMS precursor in the worts. Consistently, LMB 1 had lower amounts of DMS and DMS precursor compared to LMB 2.

When the authors looked at DMS levels after fermentation, the results were quite clear, as well: a longer boil not only brings down the amount of DMS and DMS precursor in the wort, it also consistently reduces the amount of DMS in the resulting beer.

Influence of Boil Time on DMS Levels in Wort and Beer

The paper concludes that the DMS content in beer can be controlled almost impossible from other influencing factors through the right boil length and temperature. There is one exception though: if the DMS comes from another source than DMS precursor, a longer boil doesn’t reduce besides the normal evaporation.

Just like I hypothesized in my previous article, I will mention this again: I think that the literature is quite clear in that the wort boil has a large influence on DMS levels in beer, just like the specific metabolism of the yeast strain has a large influence, and that in the Brülosophy exbeeriment, the experimenters were just “lucky” in getting the right malt with only low levels of DMS and active DMS precursors, and a yeast strain with only low DMS production.

Sources of DMS in Beer

Quite often, when I run into an issue or a question related to homebrewing that is not answered in the usual homebrewing literature or forums, I turn towards scientific literature. One great example is the Journal of the Institute of Brewing, which makes its issues freely available, with literally more than a hundred years of back issues available.

When earlier today, Brülosophy posted lab results about their DMS exbeeriment, their closing statement irritated me a bit:

But, it’s just as possible our understanding of the relationship between DMS and boil length is simply lacking, that our access to modern technology, higher quality ingredients, and better knowledge about brewing processes has reduced the likelihood of problems brewers of yore had to worry about.

That sentence really made it sound like brewing science is only in its infancy. But that’s definitely not the case. Modern brewing science is lots and lots of organic chemistry, microbiology, and even genetics nowadays, so it would be hardly believable that we knew very little about DMS. I vaguely remember seeing an article about DMS on the mentioned journal, so I dug it up, and first posted a link to it in the comment section of that Brülosophy article. But then I thought, why not write about it? Because the paper itself is great.

So, the interesting that I took out of that article is that there are actually two types of DMS precursor. The paper distinguishes them as “active” and “inactive”. Both have different properties, and come from different sources.

“Inactive” DMS precursor is coming directly from the green malt. If you were to product wort from green malt, the precursor would be decomposed, and the wort would end up with large amounts of DMS, and still a certain amount of DMS precursor. During fermentation, parts of the DMS would dissipate through the gases being given off, while the DMS precursor would be metabolized by the yeast. The yeast wouldn’t make DMS out of it, though, hence why that precursor is called “inactive”.

“Active” DMS precursor is the type of precursor that is created out the inactive precursor during the kilning process. After wort production, there would only be a small amount of DMS in the wort, but still a relevant amount of “active” DMS precursor. During fermentation, that DMS precursor is metabolized by the yeast, which makes DMS out of it. Hence the “active”.

This has some interesting consequences. If the kilning can be done in such a way that no “active” precursor is found in the wort, the yeast will not produce any more DMS during fermentation, and the total amount of DMS in the beer is limited by the amount of DMS in the wort right before pitching. It can even be assumed that some of that DMS will be lost during fermentation. The authors suggest that the amounts of DMS formation during wort production need to be controlled, though. In their experience, it is easier to control DMS levels in beer if it’s derived from DMS precursor in the wort, as the final DMS level can be controlled by using a suitable yeast that keeps DMS production low.

And I think the last bit is the crucial point in the Brülosophy exbeeriment: it’s not that a 30 minute boil vs a 60 minute boil doesn’t have any impact for DMS levels, it’s just that both the specific qualities of the malt and the specific metabolism of the employed yeast do matter, and can have a large impact. My guess is: in the exbeeriment, exactly the “right” malt was used (Bestmalz Pilsner malt, apparently), combined with a yeast strain that only produces low levels of DMS (WLP029, a Kölsch yeast strain). And that perfect combination gave a result that made a 30 minute boil indistinguishable from a 60 minute boil in terms of DMS levels. That said, I would really like to see the same experiment done with a different malt (maybe a less modified floor-malted Bohemian Pilsner malt?) and a yeast strain known for greater DMS level, like a lager yeast. W34/70 comes to mind, for example.

Vienna Lager: the Aftermath

The result.
The result.

As blogged previously, I had looked a bit into the historic roots of Vienna lager, a beer style that was quite successful in the 19th century in Europe, but has since then been forgotten in its country of origin, and had only been revived through the US craft beer movement.

In April, I finally managed to brew the beer, and it fermented and matured in the weeks afterwards. It’s been lagering for a while, but a few weeks ago, it was finally ready and also finished carbonating (I had kegged the beer and force-carbonated it). The end result is a good, quaffable lager at 5% ABV, though a bit rough around the edges.

What I do like about the beer is that it just puts the intense maltiness of Vienna malt in the foreground, accentuated by a bit of residual sweetness due to a very poorly attenuating yeast. What I don’t like so much about it is how the hops play together with this residual sweetness: even though I only used Saaz hops as the sole hop addition for bittering, the beer got a very spicy hop flavour. That would be great in a dryer beer, but with 4°P final gravity, it’s just a tad too sweet, and that just clashes a bit. Don’t get me wrong, it’s still a good beer, and I’ll happily drink it, but the next one I’d do differently. Definitely a better attenuating lager yeast, and maybe a different hop variety. I think I really need to research Austrian 19th century hops wrt. to what Anton Dreher used in his beers. As mentioned in one of my previous articles, it’s very unfortunate that Austrian hop land races were (presumably) lost either due to illnesses (which ultimately brought us Styrian Goldings) or a forced stop of any hop-growing activities by the Nazis (as it happened in Mühlviertel, Upper Austria).

Another lesson that I learned was that the WLP820 yeast strain, at least in its first fermentation, is extremely slow. I even employed a quick lagering schedule with which I had had success in previous beers, but it still took 3 weeks until fermentation completely stopped. At least it behaved pretty much as expected, and was only a tiny bit more attenuative than its historic predecessor. Starting at 13°P original gravity, it fermented down to 4°P, while brewing records show something closer to 4.5°P to have been the beer’s final gravity. That’s fine with me, really.

All in all, it was definitely an interesting exercise, with a tasty outcome, and I really learned what works and (more importantly!) what doesn’t with Vienna lagers.

Brewing a Vienna Lager

About a month ago, I posted about some things I found out about Vienna lagers, and how the historic original probably was like compared to modern versions of that style.

So yesterday, we finally got around to brewing it on my own. I compromised a bit in the whole process, though, just to make a few things a bit easier for me. In particular, I decided not to do a decoction mash.

I use a Weck preserving cooker as a mash tun, as it can contain plenty of liquid for the mash, and it’s electrically heatable, allowing to go through specific rest temperatures without having to resort to having to add hot water later. Just don’t trust the internal thermostat, and use a proper food thermometer instead.

I used 20 liters of water at 66 °C, and mashed in 5.3 kg of Vienna malt. The resulting mash was at 62 °C, and from there on I did a simple Hochkurz infusion mash:

  • 30 minutes at 62 °C
  • 20 minutes at 72 °C
  • 10 minutes at 78 °C

For modern malts and a high degree of diastatic base malts (like 100% in this case), that’s good enough to fully convert all starches.

After an iodine test showed that all starches were indeed converted, we continued with lautering. For that, we use a simple bucket from my preferred homebrewing online store, with a Mattmill false bottom.

For sparging, we always employ a colander with a food container lid set in the middle, to sprinkle hot water on the mash. BTW, my hot water is… my boiler. My flat contains a large boiler that actually delivers 80 °C hot water. Perfect for sparging.

 

The collected wort showed a pre-boil gravity of about 12 Brix, which later turned out to be probably not quite exact. I think I need to recalibrate it with distilled water. *sigh*

Anyway, we boiled it for 90 minutes, with 60 grams of Saaz hops for bittering, and no other hop addition.

After a whirlpool, I moved the wort to a fermentation bucket, and cooled it down to 20 °C with an immersion chiller, then moved it to my keezer to further cool it to 11 °C.

The hydrometer showed a bit more than 13 °P as original gravity, while the refractometer showed 14 Brix. A recalibration really seems necessary.

Finally, in the evening, I pitched a starter of WLP820 yeast. That should give a low attenuation comparable to the lager yeast that was used in the 19th century in Anton Dreher’s brewery. The beer is going to ferment in the next two weeks or so. I’ll use Brülosopher’s quick lagering method, as I’ve had some good experience with it in previous batches of lager brewing.

As soon as the beer is finished lagering and carbonating, I’ll post a report about the final result.