Category Archives: Brewing

A Refreshing Golden Ale

I recently brewed a Golden Ale that I would like to briefly introduce. Even though I brewed only about a month ago, the beer is already drinkable and in my opinion absolutely fantastic. And it’s such a simple recipe, a “SMaSH”, but I didn’t specifically design it to be one, it just happened to be one.

Here are the basic numbers:

  • OG 11.25 °P (1.045)
  • 4.6 % ABV
  • 30 IBU (calculated; Tinseth)
  • ~6 EBC

The grist is just 100 % Extra Pale Maris Otter, which I mashed at 68 °C until fully converted. The hopping goes like this:

  • 1 g/l Brewer’s Gold (6.8 % alpha acid) @ 75 min
  • 1 g/l Brewer’s Gold (6.8 % alpha acid) @ 10 min
  • 1.5 g/l Brewer’s Gold (6.8 % alpha acid) @ 0 min

As yeast, I chose Nottingham Ale dry yeast, and just let it ferment at room temperatures, so it rose to probably something like 22 to 23 °C.

Now what’s so special about this beer? Well, for one, for such a young beer, it’s incredibly drinkable. Besides that, it’s a great showcase for German Brewer’s Gold hops. In typical descriptions of this hop variety, it is characterised as quite pungent, and more recommended for bittering than anything else, but I have to reject this notion: it is equally usable as aroma hop, as it adds typically “British” herbal-floral-spicy notes, complemented by a citrus note that is relatively subtle and not in-your-face like American varieties but still more pronounced than other traditional English hop varieties. And these characteristics even show in Hallertau terroir.

Brewer’s Gold was originally developed at Wye College about a hundred years ago, and to my knowledge, isn’t grown much in the UK anymore. For whatever reason, it still seems to get grown to a certain extent in Germany. I got my hops through a hop order directly pretty much directly shipped from a hop grower in the Hallertau, organised through a German homebrewing forum.

In my case, I bottled the beer with a relatively low carbonation, so as a bright, hoppy beer, it is the closest to fresh cask ale you can get under these circumstances. When this batch is finished, and it probably won’t take too long, I’ll definitely consider rebrewing this beer, which is something I don’t normally do.

Why There Is No Farmhouse Brewing Tradition in Austria

Beer is a common people’s drink, and in quite a few countries all over Europe, it was brewed at home, by farmers, which led to all different kinds of farmhouse brewing traditions, like the origins of the Belgian/French Saison style, or the farmhouse brewing still practiced in the Nordic countries and Lithuania. There is so much diversity in farmhouse brewing that you can literally spend years on research and writing about it.

Since beer in Austria has such an importance, I always wondered whether there was any farmhouse brewing tradition there. I asked my grandmother whether she remembered in her childhood and youth, and she said there was absolutely nothing like it. On the other hand, producing Most (pretty much like cider) from apples and/or pears seems to have been more prevalent, especially in rural areas of the region where I come from. But it was nothing I put more thought into until I stumbled upon a series of books from the 1930’s describing the history of brewing and hop growing in Upper Austria.

These books give an interesting insight into how brewing was organized since the middle ages: hop growing has been documented since the early 13th century near the monastery of Wilhering. The hops grown actually had to be delivered as natural goods, which was called “Hopfendienst” (literally “hop service”). And beer brewing was very similar: the monastery of St. Florian documents 27 surrounding farms between 1378 and 1445 that had to do “Bierdienst” (“beer service”).  At that time, it was already possible to pay money instead of delivering beer, which suggest that there may have been a time where there was no alternative to delivering beer.

But it also shows that beer brewing by farmers was on its way out: at that time, the right to brew was shifting from farms towards cities and market towns. Cities like Linz, Freistadt and Enns received the privilege of “ban miles”, which prescribed that no other pubs and no brewing were allowed in a certain distance around these cities. Brewing became a privilege of the citizens, which often formed brewing communes or took turns in brewing through a publicly organized lot system. With this also often came restrictions on the sale of imported beer, which ensured that local beer was consumed locally.

Besides the cities and towns, monasteries also brewed beer: Wilhering used to have its brew house, which even burned down and had to be rebuilt in the 17th century, and so did the monastery of Schlägl. This brewery still exists in this day and age, but historic records before the 17th century were lost due to a fire in 1626.

In one case, the old concepts of brewing communes also survived into the modern era: the city of Freistadt not only has brewing privileges at least since 1277, it also has the last brewing commune in Austria. In the 18th century, its citizens decided to build a brew house and concentrate the brewing efforts. This brewery, Freistädter Brauerei, still exists today, and so does the ownership structure: every house within the city walls comes with shares of the breweries, and the right to a certain amount of beer every year. If you buy a house in Freistadt, you also become a co-owner of the brewery.

So, for centuries, brewing in parts of Austria has been absolutely dominated by cities and market towns, which had exclusive brewing rights. Already towards the end of the middle ages there were efforts to stop farmers from brewing beer, and since no farmhouse brewing is recorded since then, it seems like it was quite successful.

Of course it is too simple to say that there was no farmhouse brewing at all in Austria. There are actually records of a farmhouse brewing tradition in certain parts of Austria, in particular in Carinthia. There, stone beer was brewed by the local farmers, from oats, barley and wheat, employing hot stones to heat the mash in simple wooden mash tuns, without boiling the wort. When the Austrian government tried to supplant this very traditional beer style with modern brown barley beer, the lawyer of a Carinthian abbey gave his expert opinion, in which he stated that stone beer was the only drink available to field workers on the farm, and taking away their beer would deny them their refreshments after a week of hard work. He also stated that only oats and low-quality wheat were used instead of high-quality ingredients.

This is probably the only record of a brewing tradition (and possibly right) outside of cities and market towns that can be truly considered to be farmhouse brewing. I am not a really sure why the specific rights of Carinthia and Upper Austria differed so much, but my guess is that Carinthia and Upper Austria were simply governed differently: even though they were both in the sphere of influence of the Habsburgers, they were still legally separate duchies resp. archduchies.

Interestingly enough, descriptions of this Carinthian farmhouse brewing tradition seem remarkably similar to elements of other European farmhouse traditions: the use of juniper (which is a huge topic on its own), the use of hot stones for mashing in primitive wooden mash tuns, and unboiled wort.

To summarize, we can certainly that due to power structures in large parts of Austria, brewing outside of cities and market towns, in particular by farmers, was actively discouraged and regulated through brewing rights. The only well-known exception to this is Carinthia, where a unique stone beer tradition was alive until the early 20th century. But even this tradition has long died out, which is way we can definitely say that there is no more farmhouse brewing in Austria, and there hasn’t been any in most parts for at least 500 years.

If you want to read more on this, the Upper Austrian state library has the multi-volume work “Brauwesen und Hopfenbau in Oberösterreich von 1100 – 1930” (brewing and hop-growing in Upper Austria from 1100 to 1930) freely available in digitized form.

My 2016, Summarized

Plenty of stuff happened in 2016. Even though I only do the blogging on the side, I got a few things done of which I’m quite proud.

First of all, I managed to self-publish my first (German-speaking) e-book about historic beer styles. It’s a bit rough around the edges, but it was a good experience to work on it, and it will form the basis for a more comprehensive, in-depth, English-language e-book about the same topic. You can download my e-book here, for free and all.

I also posted a series of articles about the German purity law and the unhistorical narrative around it that has been published by the German Brewers Association at its (supposed) 500 year anniversary.

Then I spent some time researching old beer styles: first Horner Bier, a refreshing old Austrian beer style brewed exclusively from oat malt, then Mannheimer Braunbier, a once common brown beer that was brewed with juniper berries, and then a whole lot of other styles most of which made it into my e-book. I even brewed Horner Bier at home, and it turned out to be nice. Also Berliner Weisse: I joined up with Franz Pozelt, and we first brewed an unboiled Starkbier version based on a historic recipe involving barley malt, wheat malt and oat malt, and then a more modern version at normal Schankbier strength. I also attended the Berliner Weisse Summit, which was pretty amazing.

In summer, my wife and I visited Bakewell and the Peak District, and then York for a week. This included not only visits to a lot of pubs (I can particularly recommend the Phoenix Inn and the Maltings in York, and The Manners in Bakewell), but also two brewery visits, first Cloudwater in Manchester, then Thornbridge in Bakewell. We also visited Thornbridge’s Peakender Beer Festival, which is great if you like Thornbridge beers, and the Portrush Beer Festival in Northern Ireland, which was fantastic to get an insight into the growing craft beer scene of Norn Iron.

On the lager brewing front, I played a bit with Munich Helles, my wife’s favourite beer style, and found what works best for us: 98 % Pilsner malt, 2 % CaraHell, 100 % Hersbrucker hops, and Wyeast 2308 yeast. Other tries that worked alright but not as great involved 100 % Pilsner malt, Hallertauer Mittelfrüh or Perle hops, and W-34/70 yeast. What absolutely did not work out was 2 % CaraMunich, Saazer hops, and Mangrove Jack’s M76 Bavarian lager yeast: way too fruity, and outright weird. Most likely because of the yeast. And as a final surprise of the year, the chest freezer on a thermostat that I’ve used for keeping exact fermentation temperatures broke in such a way that it’s irreparable.

So, what’s the outlook for 2017? First, I will continue my work on an English-language e-book about historic beer styles. Then, I will need to look into an affordable replacement so that I can continue brewing lager beer at home. And lastly, beer festivals: we’ll be going to the Manchester Beer and Cider Festival in January, and the Great British Beer Festival in August.

And of course, 2017 will hopefully be full of lots of great, homebrewed beer.

Brewing a Historic Berliner Weisse

It’s March, and I’ve been wanting to brew a Berliner Weisse for quite a while. So what better time to brew a Märzen-Weisse?

Relatively little is actually known about Märzen-Weisse. What is known is that it’s a stronger version of a regular Weisse. In his 1947 brewing notes, the brewmaster of Groterjan brewery mentioned a high-gravity version of 16-18 °P that some breweries produced occasionally. I don’t know whether that’s the Märzen-Weisse strength, but it definitely sounds intriguing.

For this brew, I teamed up with Franz Pozelt of Slowfood Berlin, to do one Weisse according to my recipe, and then one Weisse according to his recipe. Last Sunday was the first of two brewing dates.

We started off with a historic Berliner Weisse recipe that calls for 20 parts pale barley malt, 10 parts wheat malt, and 2 parts oat malt. We didn’t know where we’d end up in terms of gravity (because it’s a no-boil recipe, see below), so we used 4 kg Pilsner malt, 2 kg pale wheat malt, and 400 g oat malt.

The mash schedule was also based on historic methods: with dough-in at about 40 °C, we then slowly rose the temperature until we reached 50 °C to rest for 15 minutes. Then we continued to slowly heat up until we reached 62 °C, which we held for 45 minutes. We then drew a thin decoction and boiled it for about 5 minutes. At this point, we also added the hops, literally 3 leaves of Hersbrucker, to boil it. Mash hopping is another historic method in Berliner Weisse.

We then mixed the decoction back to raise the temperature to 72 °C, held that temperature for another 15 minutes, and then moved the mash to the lauter tun. With enough vorlauf to achieve a bright and clear wort, we then went on to sparge. Since this was going to be a no-boil Berliner Weisse, we didn’t know what efficiency to expect, so we simply collected enough wort until we reached 16 °P.

The wort was then heated up to 95 °C, and the temperature held for 20 minutes. This was a bit of a compromise, as older recipes lauter directly to the cooling tub resp. the fermentation vessel, but the Groterjan brewmaster mentions this as a possibility to prevent beer infections (such as Pediococcus) without having to resort to a boil. Interestingly, the resulting wort had 17 °P. That may be due to a measurement error earlier, and we didn’t mix the wort properly before (my experience is that during lautering, the runnings don’t mix well, most likely due to different specific gravity, so you get wildly different measurements with the refractometer depending where you take your sample).

Right after that, the wort was transferred to the fermentation vessel, and cooled down to 30 °C.

Fermentation itself is where my approach deviates from history: to better control the resulting sourness, I decided to sour the wort with a big starter of Wyeast 5335 Lactobacillus buchneri, and when sourness will have approached a good level, yeast will be pitched. I decided for US-05, as it’s a relatively neutral ale yeast which has been shown to successfully ferment even in wort with a pH level of 3.38, plus it’s cheaper for me to get several sachets of it than e.g. a single vial of WLP029 or a smack-pack of Wyeast 1007.

Since the brewday went without any issues, the lacto is doing its work now, and I’ll keep measuring the pH levels and tasting the souring wort. The yeast will be pitched when the sourness is right. In addition to that, the fermentation vessel was used to ferment and mature a batch of porter with Brettanomyces, so I expect an infection with B. claussenii, as well, which is perfectly fine for the style.

I’ll report about any results. At the moment, the lactobacillus is slowly fermenting away, producing some CO2. I suppose that’s fine, as L. buchneri is heterofermentative.

500 Years Reinheitsgebot? Let’s Discuss

In 2016, the German Reinheitsgebot (beer purity law) is being celebrated to be 500 years old. According to some official document from 1516, beer is only meant to be brewed from barley, hops, and water, and has been the only brewed like that since then in Bavaria, and later in all of Germany. Or so they tell us.

Briefmarke 1983 Reinheitsgebot

I, for one, am highly suspicious about this. My research into historic brewing, both in Germany and Bavaria, have shown me otherwise, that these are neither supported by documented historic brewing practice nor by the legal situation of that time.

The Reinheitsgebot’s lobbyists proponents is mainly Deutscher Brauer-Bund e.V. who have prepared a website with lots of information for the anniversary, including a list of Frequently Asked Questions, to inform the public about this supposed 500 year old tradition that only wants the best for all of us beer drinkers. Having sifted through that material, I stumbled upon imprecise language, which is corrected and/or justified in other places. I suspect that the Reinheitsgebot proponents exactly know about all these imprecisions and inconsistencies, and yet resort to them because they serve a purpose.

I find this highly problematic. I therefore decided that I will present my view on these matters in a “Frequently Questioned Answers” format, where I will point out and correct imprecisions and inconsistencies, all based on facts and backed by sources. In addition that, I will explain why I think the Reinheitsgebot, the official narrative around its history, and its practical implementation in the form of the current German beer-related legislation is not only unhelpful to German beer culture, but how it has also helped erase the rich historic Bavarian and German traditions that have gone beyond just barley, hops and water.

With this series, I plan to further and enrich the discussion about the state of German beer and the planned 500 year celebrations, and help the discourse about the future of German beer.

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.