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Double-Decoction Mashing on a Home-Brew System Not Designed For Decoction: A Post-Mortem

Today, I brewed together with Ben Palmer at the MASH PIT, a kind of nanobrewery/home-brewing co-working space that allows you to brew your own beer on the brew kits installed there. Ben had recently moved to Berlin, and since we knew each other through Twitter, we met up and eventually decided to brew a beer together.

One thing that I’ve been wanting to do for a long time at the MASH PIT was to brew a beer using a decoction mash. Ben was also happy to do that, so we agreed on a simple recipe. Our grist consisted of 98% Pilsner malt and 2% CaraMunich II, while the hops we chose were Celeia (Ben had never used Slovenian hops, and since I hadn’t either, I was happy to also try them out). The original idea was to ferment it with a Kölsch yeast, but since we were informed that the MASH PIT had run out of that yeast the day before the brew day, so we substituted it with Nottingham Ale yeast instead, another fairly neutral and attenuative top-fermenting yeast. For mashing, we wanted to do a double decoction, for several reasons: my reasons were that I wanted to try brewing a double-decocted beer on the MASH PIT kit, and I also wanted to try brewing an ale of some sorts that had a distinct decoction character. This was something I had stuck in my head ever since my last visit to Prague, where I tried a few ales [sic!] from Pivovar Matuška, and they all had a distinct “Czech” flavour that I could only attribute to decoction mashing. Ben’s reason to try out double decoction was that he hadn’t really much experience beyond a few demonstrations at his vocational school.

A few words on the MASH PIT brew kit: it is fairly simple and straight-forward. It consists of three large pots of maybe 75 litres volume (the scale only goes to 65), all equipped with taps on the bottom and the top and embedded thermometers. One of these pots is sat on a gas burner and mainly serves as kettle to boil the wort as well as to heat up the liquor (brewing water). The middle pot serves as mash and lauter tun and is equipped with a removable false bottom. It also comes with a RIMS attachment that allows you to pump wort (a liquid pump is part of the setup) from the false bottom through the attachment and sprinkle it again on top of the mash. The attachment has a heating element that can be turned off and on. With this setup, you can do a multi-step infusion mash fairly easily. The third pot is also equipped with an electric heating element and mainly serves as hot liquor tank (HLT). Through three switches, you can turn on and off pump, RIMS heating element and HLT heating element.

But instead of following this scheme, we instead decided to repurpose the kit for decoction mashing. With about 11 kg of grist, we filled the mash tun with 44 l of liquor at 45°C, then mashed in. This increased the overall mash volume to 55 l. The mash temperature was 41°C. After a short rest, we pulled 36 l (i.e. two thirds) of thick decoction and moved it over to the kettle. We brought the decoction up to a temperature of 70°C, which went very quickly thanks to the powerful burner. A quick rest of 15 minutes to at least partially convert the available starch, and then brought the mash up to a boil. That’s where the problems started: we had a bit of a boil-over, which was our mistake as we partially covered the pot with the lid and also kept it unwatched. After a quick cleanup and making sure we hadn’t lost much of our decoction, we continued boiling it for another 10 minutes.

A watched pot never boils, an unwatched pot boils over.

We then started mixing the decoction back into the main mash. We noticed that even though we had moved only about 50% of the decoction, we were already overshooting our target temperature of 65°C. That was not good. We had to improvise somehow, and so we decided to add some more cold water to the decoction to bring its temperature down. We eventually got that done and ended up with a mash at pretty much exactly 65°C, but now with a total volume of more than 60 litres, which we left to rest for 50 minutes.

So obviously we had overdone it with the decoction volume. I had chosen two thirds as the initial volume because that’s what had worked for me at home on my home-brew kit. Except my kit at home is for 20 litre batches, while this system is for 50 litre batches. I realize that my home system is at such a small scale that boiled mash can cool down fairly quickly, but I didn’t think that effect would effectively disappear at at scale-up from 20 to 50 litres.

The change in mash volume also meant that any previous estimations of the volume for the second decoction were out the window. We then decided to just estimate it to one third of the total volume, and then a bit, so the second decoction we pulled was thin and sized at 25 litres.

We brought this second decoction again to a boil, boiled it for 5 minutes, and then mixed it back again. By that time, the main mash had cooled down to 61°C, so the final temperature after mixing back was only 71°C. Not exactly the 75°C where we wanted to get to, but still good enough. We then left the mash to rest for another 30 minutes and prepared for lautering and sparging: we cleaned the kettle, filled up the HLT and heated the sparging liquor.

With everything prepared, we decided to just skip the iodine rest (YOLO, right?) and started a vorlauf. We only got very few hard bits and very quickly got a very clear wort. We then connected the mash/lauter tun’s tap to the kettle, and slightly opened the tap. Lautering went quickly and ran off smoothly, looking very clear and bright. We then started sparging by pumping liquor from the HLT onto the mash, breaking up the stream with a highly technical piece of equipment: the mash paddle.

Kettle in the front, sparging action in the back

We managed to collect a total of 63 litres of sweet wort. In the end, this was limited by gravity: at 63 litres, the level of the wort was the same as the tap of the mash/lauter tun. We then starting bringing the wort to a boil.

Ben then had the idea that we should check the gravity of the last runnings with the refacrometer that we had used to check on gravities during the process. Turned out, the “last” runnings still were at more than 5°Brix. Instead of just conceding to the laws of gravity, we should have lautered the last remains into a separate vessel and topped off the kettle instead. It probably would have also helped with another issue we noticed: according to the refractometer, the pre-boil gravity was at 12.4°Brix. Our plan was to have an OG of 11.8°P (°P and °Brix are very similar scales, and virtually identical and practically interchangeable). So strangely, we seemed to have a much higher OG to expect than what we had planned and calculated. Of course, we didn’t know what extract efficiency to expect on this home-brew kit, but still.

We decided to continue with boiling the wort anyway, and added hop additions at 90 minutes and 5 minutes before flame-out, and then more during whirlpool. Post-boil gravity according to the refractometer was at 15°Brix. This was way too much, and would have meant a much greater efficiency than what we could have planned for.

We then sent the hot wort through the plate chiller to the fermenter at a nice 18°C, and measured the OG using a saccharometer. It really was at 14.1°P. This was weird, a difference of almost one degree. I then rechecked the refractometer with just water, and it turned out that refractometer wasn’t properly calibrated.

Another problem also popped up when pumping the wort from the kettle through the plate chiller to the fermenter: towards the end, we started pulling in hot break and hop particles. We were then told that they actually had a hop filter that we should have attached that would have allowed us to get more of the wort from the kettle to the fermenter without sucking up any of the gunk. We had to stop the pump early, and only ended up with about 45 litres of wort, but at a higher OG than we what we wanted.

Our solution to that was simple but almost embarrassing: we decided to dilute the wort with cold water to bring the OG down to 12°P. The final step was then to hydrate the yeast (3 sachets of Nottingham Ale yeast should do just fine) with some fresh wort, pitch it, and move the fermenter to the temperature-controlled fermentation room.

The day was concluded with lots of cleaning up and a glass of cold, fresh beer from the MASH PIT tap room. A lot of things went wrong during the brew day, but we managed to salvage any issues, and still arrived at something that I think should come out pretty nicely. I’m definitely looking forward to trying out the resulting beer. The main things I want to see is whether I really do get a pronounced decoction character in the beer, and of course, what Celeia hops taste like in a beer.

A brewing selfie. We were smiling under these masks, I swear.

“Vienna Lager”, My New Book

Today, I am publishing my new book titled “Vienna Lager”. It’s the result of 1.5 year of intense research about the history of the Vienna Lager beer style and its current state. And of course, how to brew it.

I consider this to be my greatest work so far, and I’m absolutely proud about the result. I achieved everything I wanted to achieve in this book: first, I managed to put together the history of Vienna Lager in Austria from its very beginning in the late 1830’s until its demise after World War I in great detail, all embedded in the history of its inventor, Anton Dreher, and his brewery in Klein-Schwechat near Vienna. Second, I was able to shed more light on the supposed survival of Vienna Lager in Mexico. My research very quickly showed that it wasn’t Mexico that was big in brewing Vienna Lager, it was the United States! This is something many will be surprised about, but Vienna Lager was a fairly popular style in the US, and even survived Prohibition to a certain extent, until it made it into the canon of classic beer style as we know it nowadays. And third, I could reconstruct how Vienna Lager was brewed, from the ingredients to the brewing process, fermentation and lagering. I have previously discussed elements of this here in my blog, but in this book, I can finally present all the sources that corroborate even the tiniest detail about historic Vienna Lager brewing.

So today, I’m releasing the book both as printed book and e-book, exclusively on Amazon. You can find more information about the book including links to Amazon on vienna-lager.com.

As with my previous book, I tried to keep the price moderate to make it affordable for everyone. While “Vienna Lager” is more extensive compared to my previous book, I deliberately decided to keep the price for the e-book the same. As for the print-of-demand book, I had to slightly increase the price to offset the increased printing costs. For every book sold, I roughly get the same amount of royalties, no matter which media. I think this is fair, as I’m happy with the individual royalties that I earn, while being able to keep the costs down for interested readers. Ultimately, we have to face the hard truth: there is not a whole lot of money to be made as an author in a niche topic such as beer history and home-brewing. And that’s not my reason why I decided to write about historic, extinct German beers or Vienna Lager in the first place: instead, I wanted to let everyone know about everything I’ve been able to find out about these beer styles. Which brings me to my next point…

The history about Vienna Lager, as communicated in many works in the general beer history and craft beer sphere, has not been of great quality up to now. I’m not going to name names, but some books are outright works of fiction, while others suffer from something that’s called the Woozle effect. I didn’t know the term until a few months ago, but it’s what I had observed for quite a while: unsourced claims or historic stories frequently get cited even when they lack any historic factuality. The existence of citations creates an illusion of authority, which in turn gives credence to these claims, and generates even more citations which in turns boost the illusion of authority, and the spiral continues. The more citations are found or the same historic-sounding story is encountered, the more it seems like it’s true. The historic narrative around Vienna Lager is certainly not unique (IPA and Porter for example have long suffered from similar problems, and despite beer historians like Martyn Cornell, Ron Pattinson and others trying to correct them, they still cling on), but it’s the topic that I’ve researched fairly extensively for 1.5 years and that is now closest to my heart.

So this is my attempt to correct the narratives, and ironically, the real history of Vienna Lager is much more exciting. There is just so much we got wrong that got perpetuated over the years. Probably the most prominent example is the narrative that Vienna Lager supposedly survived into the 20th century due to Mexican brewing tradition. You often find stories of some unnamed Austrian brewers or German or Swiss brewers like Santiago Graf or Emil Dercher who supposedly went to Mexico (the Austrian brewers are often associated with Mexican King Maximilian, who, as a Habsburger and younger brother of the Austrian Emperor, was of Austrian descent) and started brewing Vienna Lager there. From everything I could gather, none of that was true. While brewers like Dercher and Graf definitely existed and (especially in the case of Santiago Graf) had great influence on brewing in Mexico, their connection with Vienna Lager is very doubtful.

But the real truth behind is actually much more interesting: up to the 1880’s, beer in Mexico was an imported niche product mostly enjoyed by expats or rich European immigrants. Most alcohol consumed at the time was agave-based, either just fermented (pulque) or distilled (mezcal). The first brewers didn’t have the conditions to brew cold-fermented lager beers, either, but instead brewed top-fermented beers from locally sourced ingredients such as sun-dried barley malt and unrefined cane sugar known as piloncillo. There are exceptions to it, like one German brewer allegedly building a small lager brewery including lagering cellars on the slopes of mount Popocatépetl, but lager brewing was only a necessity introduced the fight back American imported beer that came into the country after Mexico and the United States were better connected by railroad. That’s the kind of history of early Mexican beer that I actually find more interesting, and which in my opinion should be researched more thoroughly as it makes for a much better topic than just the narrative of Vienna Lager in Mexico.

But enough spoilers.

And there is one more thing I want to emphasize: I can’t even blame any of the writers that perpetuated any of the stories that we’ve previously heard about Vienna Lager that turned out to be not quite true. That’s what used to be the only material accessible to English speakers, and even for German speakers, there wasn’t a whole lot of stuff around (by now, the situation has slightly improved; in particular the history of brewing in Vienna independent of Vienna Lager is really well-researched and well-presented). In that sense, I very much recognize my privilege in being a native German speaker with sufficient proficiency in English that allowed me to research the topic based on original sources and to communicate my research results to a wider audience in English.

Of course, I wouldn’t have been able to complete my work without the help of many other people. In particular, I’d like to thank my wife Louise for supporting me in writing my book and for her tolerance of my obsession with the whole topic. I’d also like to thank everyone who inspired me to write this book, who provided me with interesting source material, or who supported me by giving me lots and lots of valuable feedback: Boak & Bailey, Ron Pattinson, Gary Gillman, Geoff Latham, Jeff Alworth, Joe Stange, Johannes Kugler, Michael Williams, Michelle Humphrey, Sven Förster, Michaela Knör, Glen and Julie, Doug Hoverson, Stan Hieronymus, Dave Carpenter, Mark Dredge, Natalya Watson and Benedikt Koch. A big Thank You to all of you!

Here are some of the online resources that I used for my research:

A few more geeky details: I wrote the book using Visual Studio Code in Markdown format, and used pandoc with custom templates to render it into epub as well as a print-ready PDF (via LaTeX). When all the dust has settled, I intend to publish a whole template to produce books for self-publication in the same way I did it for my last two books. The book cover design is self-made: as background image, I used a historic map of Vienna from 1875, while the book title itself was inspired by Vienna’s iconic street signs and made possible by the Wiener Norm font which is freely available under a Creative Commons license.

“OK, great, what’s next?” some of you may ask, and to be honest, I don’t know yet. Originally, I had planned a lot more around the launch of this book, but due to The Event that has plagued us since at least March 2020, and the necessary precautions due to it, much of that simply has not been possible. I hope to be able to do something like a proper launch event at a later time, and will announce this accordingly in case it will actually be possible in the near future.

If you think the topic of my new book is interesting and more people deserve to know about it, please spread the word and tell people about it. If you have a blog, write about, if you have a beery podcast, feel free to get in touch with me and I’ll happily talk about Vienna Lager with you.

For now, enjoy the book, enjoy Vienna Lager, if you’re a home-brewer, or even a pro brewer, go and brew some. Cheers!

Hansla: the Revival of an old Beer Style

Germany is slightly opening up. ICE trains are going again, and in Bavaria, hotels and holiday apartments are again allowed to open and host tourists. Since we’ve been practically locked in for almost 3 months, my wife and I decided on a short notice to go to Bamberg for a quick trip.

The ICE from Berlin to Bamberg is quick, less than 3 hours with just a few stops. Our holiday flat was located near Wunderburg, a small district of Bamberg a bit off the town center which is best known for its two breweries that are practically opposite of each other, Keesmann and Mahrs Bräu. Most of the days were rather rainy, which was a good opportunity to walk around a bit, enjoy the scenery of this historic city, and then find the good places for beer. And, amazingly, physical distancing both in pubs and beer gardens worked really well all across Bamberg. Everyone was compliant, wore masks where and when asked to, and kept their distance to other parties. One place, zum Sternla, even put up perspex “windows” to divide large tables for different parties.

Perspex windows!

One thing that I had noticed in the weeks before the trip, particularly on Instagram, was that Brauerei Heller, the brewery behind the well-known Schlenkerla smoked beers, had launched a new low-alcohol beer, Heinzlein. I was intrigued about it, because I knew this beer type under various different spellings (“Hainslein”, “Heinzele”) of the same name from previous research in historic beer literature. This “new” low-alcohol beer clocks in at just 0.9% ABV. While it cannot be legally considered to be alcohol-free beer, it is still practically too low to taste any alcohol or to get even tipsy from it.

In historic beer literature, this beer type is already mentioned in the early 19th century as typical for Bamberg. In the 1818 book “Das Bamberger Bier” by Johann Seifert, it is described as being brewed from the third runnings, boiled with hops, left to cool in the brew kettle overnight, and fermented with bottom-fermenting yeast like the regular beer made from the first and second runnings. The 1836 book “Die Bamberger Bierbrauerei” by Johann Messerschmidt contains an own section about brewing this beer type, and calls it a “one-hundred-year tradition” which, even though it was actually not legal according to the Bavarian brewing regulation from 1811, resisted any attempts to abolish its brewing. So, just from historic sources we know fairly well that this beer was actually brewed, and more importantly, how it was brewed.

So just from that perspective, it makes me incredibly happy to see a recreation, even with a slight modernization, of this historic beer style: unlike the historic original, the modern Heinzlein is available in two different version, a pale and a dark version. The dark version is, well, brown, slightly malty and astringent, while the pale version also has a faint astringency, but a lot more hop aroma and bitterness in the foreground, which makes it quite the refreshing drink.

In addition to that, Schlenkerla also has a version of this historic beer which they spell differently again, Hansla. It’s advertised as less than 1.2% ABV, and very obviously is related to Schlenkerla’s smoked beers. It is slightly malty, still has some smokey flavour, but also carries the tiniest hint of astringency. I was lucky to sample this beer directly at the historic Schlenkerla pub.

Schlenkerla Hansla

In the context of beer history, the Schlenkerla version of this low-alcohol beer type is probably closer to the historic original than the more modern versions.

Historic sources describe it as light and agreeable, pale in colour. Some brewers apparently sold it directly (and there was plenty of demand from poor people that couldn’t afford a Maß of full-strength beer!), while others mixed it with the regular beer.

And that’s where I also see the Hansla’s great potential: while it’s nice and refreshing to drink on its own, I could totally see a Schlenkerla Märzen mixed half-and-half with Hansla, to produce a drink that’s still obviously classic Rauchbier, but at the same time only has about 3% ABV. Or, if you prefer it slightly stronger or weaker, in different ratios. Please note that I haven’t actually tried this, but as soon as I get my hands on bottles of Schlenkerla Märzen and Hansla or Heinzlein, this is certainly an experiment I would like to conduct.

And last but not least, kudos to brewmaster Matthias Trum, who created these beers with the full awareness of the historicity. In my opinion, it’s a drink with character, in some ways a bit rough around the edges, that can meet the current trend of low-alcohol beers without giving up any of its character or originality. Especially the Schlenkerla Hansla is very much a Schlenkerla beer. Just a few years back, I don’t think anybody would have expected low-alcohol Schlenkerla that would be recognizable as such. And going even a step further, I don’t think anybody would have really expected a low-alcohol dark beer, either.

After writing all about low-ABV beer, I’m actually quite thirsty. I wouldn’t mind a Heinzlein, or Hansla, or Heinzele, or Hainslein, or however you want to spell it (the German language has been very flexible in spelling before its standardization, especially when trying to write local dialect words in high German), but it hasn’t quite made its way up from Bamberg to Berlin.

Experiment Time: Does Lactic Acid Skew Refractometer Readings?

In a Facebook group I follow, an interesting problem came up. Somebody had brewed a mixed-fermentation Berliner Weisse with brewer’s yeast, lactobacillus brevis and brettanonymces claussenii. They didn’t own a saccharometer, but instead determined their OG with a refractometer. They now wanted to know whether fermentation was finished, and used the refractometer as well to measure the beer that had been in the fermenter for several weeks.

Before I continue, a quick excursion into how refractometers work. Every translucent material bends light to a certain extent, the light gets refracted. To describe the extent with which the light is bent, the so-called refractive index is used. The refractive index n is defined as n = c / v, where c is the speed of light in a vacuum, and v is the speed of light in the particular medium. Water for example has a refractive index of 1.333. When we dissolve sugar in water, the refractive index of the solution is increased. The refractive index of a 10% glucose solution in water is 1.347, for example. This change in the refractive index can be used to indirectly measure the OG, by looking at the difference between the expected refraction of water vs the measured one, i.e. by how much more light gets refracted.

In fermented beer, this gets trickier, because due to fermentation, the resulting liquid contains ethanol. Ethanol has a refractive index of 1.361, which skews the overall measurement. Ethanol also skews the measurement when determining the FG of a beer, as its specific gravity is just 0.79. In typical fermented beers, the amount of ethanol is large enough that we need to correct our measurements to be able to estimate the actual FG. This is all fine.

The mixed fermentation opens up another problem, though. It has a refractive index of 1.427 which significantly higher than that of either water or ethanol, but in typical fermented sour beers, its content by weight is fairly low compared to e.g. ethanol. According to this presentation, typical Berliner Weisse contains 2 to 4 g/L of lactic acid, i.e. 0.2 to 0.4% by weight.

When I read about the issue of seemingly underattenuated Berliner Weisse, one of the things that came to my mind was exactly whether the lactic acid from the mixed fermentation skewed the measurement enough to cause such a large disparity that a beer that is expected to be overattenuated to come up with an apparent attenuation of just 68%.

So I asked myself the question: if I added the typical concentration of lactic acid in a Berliner Weisse (i.e. 2 to 4 g/L) to distilled water, by how much would my refractometer be skewed?

I have a refractometer at home, 2 litres of distilled water, a big bottle of 80% lactic acid, and pipets with which I can measure out millilitres of lactic acid. But how many grams is a millilitre of lactic acid? A millilitre of pure lactic acid weighs 1.357 grams, therefore a millilitre of an 80% solution would weigh would weight about 1.285 grams. Since I want to test a whole range of lactic acid content, just measuring out by ml is good enough for me.

I poured 1 litre of distilled water into a clean vessel, and calibrated my refractometer so that it shows exactly 0°Brix. I then added 1 ml of lactic acid (= 1.285 g), stirred it well, and measured again with the refractometer. I measured X°Brix. I then repeated this to up to 5 ml of lactic acid (= 6.425g), and got the following measurements:

  • 1 ml (~ 1.3g): 0°Brix
  • 2 ml (~ 2.6g): 0.2°Brix
  • 3 ml (~ 3.8g): 0.4°Brix
  • 4 ml (~ 5.1g): 0.4°Brix
  • 5 ml (~ 6.4g): 0.6°Brix

This was actually less skew than what I had expected. For a quick counter-check, I added 80% lactic acid on the refractometer, and the measurement was off the scale.

Luckily, I have a Berliner Weisse maturing at home. I brewed it a few months ago, mixed fermentation with S-04, Lacto brevis and Brett bruxellensis. I simply lautered and sparged 30 litres of wort from a 50% Pilsner/50% pale wheat malt mash, which turned out at 11°P OG (unboiled, of course). On my refractometer, I measured 5.2°Brix, while with my saccharometer, I measured 2.0°P. I used calculators to get the expected attenuation based on the OG (in Plato) and FG (in Plato) resp. refractometer reading (in Brix). For both values, I got almost the same level of attenuation (81.82 vs 82.11 apparent attenuation) as well as almost the same ABV (4.7% vs. 4.72%). This is fairly consistent with what I’ve measured earlier, namely that the amount of lactic acid in Berliner Weisse has very little impact to skew a refractometer measurement.

Nevertheless, I think it goes without saying though that a brewer should never ever rely on a refractometer alone. While I use one during my home-brewing, I only ever employ it to measure sugar content ad hoc during the brew day: it’s useful to observe saccharification of your mash, the strength of your first runnings, as well as the sugar content in your final runnings, or to get a good idea about the pre-boil gravity and post-boil gravity of your wort. It’s a tool that has its place, but for observing the progress of fermenting beer, I think it’s a much better idea to just use saccharometers. Even quite precise ones, with a scale down to 1/10 of a degree Plato, and thermometers for further correction of the measurement, are not exactly expensive.

The Session: Where I’m At

It’s been a while since the last Session. This is a special edition for The Event, kindly initiated by Alistair Reece. Remain Indoors.

I’ve been doing fine for the last 7 weeks. My company decided to implement a work-from-home policy (I’m privileged to work in IT as a software developer) on March 12, so it’s been pretty much exactly 7 weeks since this has started for me. In some ways, it was perfectly timed, as my wife had to undergo a knee operation around the same time, so it was actually good that I could work from home and be able to care for her as well.

The first time leaving the house has actually been stressful. One thing that I’m annoyed about are people who don’t care about keeping their distance or blocking a whole lot of space by needlessly hanging around outside in larger-than-legal groups. This didn’t just use to be annoyance, but rather anxiety. Mind you, this was at a time when I didn’t have a a home-made face mask (thanks, mum!). With a face mask on, I’m now feeling perfectly happy and content walking outside, even with people not keeping their distance. Even if they might not be effective, they sure do work for me at least on a psychological level.

As for beer, we were shopping wisely and bought two crates of beer from a local specialty beer shop before any lock-down measures were even announced. These two crates kept us going for quite a while. I did a quick count of how much other booze we had in the house, easily more than 40 bottles of all kinds of whisk(e)y, more than 10 types of gin, several rums, and even absinthe, vodka and fancy calvados. I put together a list in my mind of small beer businesses I wanted to still have around when this is all over, and supported them by either buying their beer, or buying vouchers from them if they offered such a thing.

My drinking has actually gone down. I don’t drink for the most of the week, and only a bit during the weekend. If I have 3 beers on one of these days, it’s already unusually much. Yesterday was such a day, as my Stammtisch has a Zoom session full of beer drinking and pub quizzing and discussing craft malts and their importance for historic beer styles, so I had three beers (Wicküler Pils, Neder Schwarze Anna, Schönramer Pils) and two small whiskeys (Koval Rye).

Stammtisch. I used to meet friends once a month for a few beers in one of the best German beer bars of Berlin, Foersters. We had a Stammtisch scheduled for March 12, but decided to move it to a Zoom call instead. We’ve kept this up, and actually met more often that we do normally, once every one to two weeks. It certainly helped me keep sane, and due to the decentralized nature of it, we’ve been able to include former regulars and friends that now live in other parts of Germany or the world.

Most of my beer writing energy has actually been going towards my upcoming book about Vienna Lager. I’m now in the final stages: I have only a few small gaps to fill, I have the printing layout set up, and a solid idea for a book cover, less beery per se but rather a nice homage to the city of Vienna itself. I’m so absolutely excited about the whole topic, as I found out so many things that have never been discussed in the context of the history of Vienna Lager, so many things that are just misrepresented and have even been forgotten. At the moment it seems quite realistic for me to publish the book in June or early July. It’s going to be kick-ass if I may say so myself.

That said, work itself has been hard-going at times. Not everything is great when you’re just sat at home for most of the time, trying to avoid distraction is hard, days just blend into each other, and you barely realize what day of the week it actually is. Weekends just pass super quickly and don’t really provide as much rest and recuperation as I would like them to do.

But in the grand scheme, I’m still doing fine.

The History of Modern Baking Yeast

Since the beginning of The Event (remain indoors!), people have been panic-buying flour. Lots of flour. More recently, some people on Twitter have also complained about how ordinary baking yeast is unavailable at the moment. For myself, that’s not an issue, as I have a healthy sourdough culture (named Penelope) that I now use more regularly to bake some delicious bread for both fun and sustenance. But others aren’t so lucky, so a question asked by many is whether brewers yeast is an acceptable substitute for baking yeast.

The short answer is: yes, they’re both Saccharomyces cerevisiae.

The slightly longer answer is: yes, just be aware that the pitching rates in baking are much higher than in brewing, so if you start using dry brewing yeast, your bakes will be very expensive. A good way to deal with this is to keep some of your yeast in the form of dough, like a sourdough, except not sour, and just regularly feed it with sugar or flour. That should make it possible to propagate the yeast for quite a while, making the last pack of bakers (or brewers) yeast last for quite a while longer.

The beer historian’s answer is: yes, they’re both Saccharomyces cerevisiae, and were a focal point of cooperation between the brewing and the baking trade. In the first half of the 19th century, it was common in Vienna for bakers to use top-cropped yeast from the local breweries. It was in fact their main source of yeast. Then something happened: in late 1840, Anton Dreher in Klein-Schwechat (just outside of Vienna) starting brewing using bottom-fermented yeast. His new types of beers became an instant hit in and around Vienna, and of course, other local breweries had to react and also introduced bottom fermentation to their breweries. This change went in fact so quick that within just five years, all the Viennese breweries had switched. The bakers weren’t happy, because that changed the yeast they could get from the brewers: while top-cropped yeast was previously plenty and of good quality, the new type of yeast was harvested from the bottom of the fermentation vessel, and was full of bitter hop compounds, hop resins and cold break (coagulated proteins), which tasted bitter and looked darker than previous yeast, making it unsuitable for baking.

The bakers first tried to import fresh yeast from outside Vienna, but this turned out to be infeasible as the yeast’s quality and health would deteriorate too quickly, so they needed to find another way to get a reliable yeast source, ideally making them independent from any brewers. So the Viennese bakers’ guild started a competition in 1845, announcing that they would award a prize to the person who could produce a leaven that was suitable for completely replacing the much sought-after top-fermenting brewers yeast.

The brewer Adolf Ignaz Mautner of St. Marx brewery went on and developed a system to industrially produce and press yeast. His general approach was fairly simple: first, a mash is produced and converted into sugar, then the mash is cooled and fermented. The resulting yeast can be harvested, washed and pressed.

For the mash, kilned barley malt and rye (in a ratio 1:2) are finely crushed and mashed in with hot water (3.5 l of water for every 1 kg of grist) to rest at 70°C for two hours. This should fully convert all starches into sugar, and also allow other contents of the malt to dissolve. This thin slurry is then chilled to about 28°C using a coolship, and then inoculated with a “mother yeast”, which is basically a smaller amount of the same type of mash that has previously been inoculated with pressed yeast or top-cropped brewers yeast and left to ferment until it is in its most active state. Essentially a yeast starter.

After about 10 to 12 hours, the fermentation is active enough to be covered with a thick foam, the yeast. This yeast is then skimmed and put onto a fine sieve that is slightly submerged in water. The idea here is to dissolve the yeast in the water, while other hard matter from the mash will be caught by the sieve. Using ice, the yeast can be made to fall out of suspension. This watered yeast is then mixed with high-dried wheat or potato starch flour, put into multi-layered linen bags, and then pressed. In terms of yield, 100 kg of crushed malt and rye produce about 8 to 10 kg of yeast, to which about 2 to 5 kg of starch flour are added.

This method is now known as “Vienna Process” and after a few improvements, it won Adolf Ignaz Mautner the Viennese bakers’ guild’s prize.

In later years, more improvements and new methods were introduced, such as a switch to green malt and corn (maize) for the mash, the introduction of single strain yeasts, as well as ways of promoting more yeast budding (and therefore a greater yield), such as aerating the mash or diluting it. These improvements increased the yield from 10% in the 1840’s up to 40% in the early 20th century. But essentially, pressed bakers yeast is still produced using methods that every brewer at the time understood, just used in a way to make yeast, not beer.

Adolf Ignaz Mautner was later made a knight of the Order of the Iron Crown, receiving the hereditary title “Ritter Mautner von Markhof”. While his brewing business was merged with the breweries of Klein-Schwechat and Simmering in the early 20th century to form a public limited company, the Mautner Markhof family remained in the food business. While family sold their business to German food company Develey, Mautner Markhof still exists as a brand in Austria, for products such as mustard (and other condiments), vinegar and pressed yeast.

And that’s how baking yeast has historically been the same as (top-fermenting) brewers yeast, and how its production was turned into an own industry by a brewer using beer brewing methods.

Book Review: “Beer: Taste the Evolution in 50 Styles”

Due to The Event, I’ve been working from home for over a week now, basically self-isolating voluntarily, and counterintuitively (but not unexpectedly), I haven’t really had a lot of spare time since then. I nevertheless want to use my free time better, support everyone out there with some fresh new content on my blog, and also get into a better rhythm to blog more. Also, remain indoors.

In December 2019, I got into a twitter conversation with Natalya Watson, discussing the minutiae of Vienna Lager history in the Americas, a conversation we then continued by email. Natalya recently published her new book, “Beer: Taste the Evolution in 50 Styles“, and she was so kind to send me a free copy as the book touched some of the topics that we had discussed.

The book’s concept is simply as it is intriguing: give a brief introduction into the history of beer based on the evolution of its four main ingredients (malt, water, hops, yeast) over time, and accompany each of these evolutionary steps with a beer that lets you experience that particular ingredient in its respective stage. Its target audience are people who are interested in beer but haven’t yet deep-dived into brewing or even the basic history of beer.

The book starts off with very brief introductions to each of beer’s four main ingredients and how they are made, grown or prepared, and what variety exists of them, followed by a short explanation of the brewing process itself. While really short, I found these introductions exactly on point, like an elevator pitch except that it tells you how grains are malted, why this is done, what types of malts exist, and how they’re used in brewing beer.

It then goes on to introduce each ingredient in greater detail: for malt, it explains the evolution from smoked malts to the invention and development of pale malts and roasted malts, to amber and pale lager beers and ales that started being brewed in the 19th century, finishing with all the different types of pale beers that have been invented in the 20th century. Each of these evolutionary steps of malt introduces you to a new beer that stands in as an example.

For the topic of water, Natalya shows by example how the composition of the local water used to heavily influence what the locally brewed used to be like.

The evolution is hops is explained by first looking at unhopped beer seasoned with other herbs and spices, then introducing landrace varieties resp. varieties of hops that were discovered and then propagated, followed by an introduction to European and American hop breeding and how it influenced beer in the 20th century, finished off with an excursion into how these recent developments in hop breeding have completely changed the beer styles of India Pale Ale.

To finish with the last ingredient, yeast, Natalya introduces the reader not just to different types of yeast, but to different approaches in fermentation, such as spontaneous fermentation and sour beers, and also talks about top-fermenting beers that have held on despite a gain in popularity of bottom-fermented lager beers within the last 150 years, as well as the influence of the science of microbiology on brewers yeast and innovations around them.

The book then finishes with an outlook into possible futures of brewing, how styles could change, and which other ingredients are available to brewers.

While I’m certainly not the intended target audience for this book, I nevertheless found it very informative. It explains some of the most important concepts of beer and brewing, and while some details were left out for brevity, all explanations seemed on point. The fun and easy to read language made the book rather captivating: I finished it in less than 2 days. The pages are colour-coded, so you always know what to expect next when turning the page, and a timeline on the top of the page guides you at what time period you currently are when reading.

As for the historical accuracy, a gripe that I have with a lot of beer books, I think Natalya did a good job in researching the general history of the beer styles that are discussed in the book. Of all the styles where I actually have first-hand knowledge, I couldn’t find any obvious mistakes. Except for one, and that was actually the start of our Twitter conversation, namely how Vienna Lager came to Mexico and persisted there. This is a pet peeve of mine, as much of the literature reiterates that supposedly Austrian brewers brought this beer style to Mexico in the 19th century. I will hopefully soon publish my book on Vienna Lager (The Event is preventing me a bit from doing research at VLB’s library), and Natalya told me she will start an errata page. Of course, do not be swayed by this detail, because the rest of the book is great.

If I knew someone who was interested in beer, and wanted to learn more about it and didn’t know where to start, then I would definitely recommend Natalya’s book to them and tell them to read the book, front to back, and then try and get the beers described in the book, and sample them while re-reading the individual sections. It certainly would get you acquainted with a large amount of different styles, and expose you to many classic beers that I think everyone should try. For the purpose of education, I think “Beer: Taste the Evolution in 50 Styles” is a great book to get started. For people who want to dive in even further, it even guides them to more beer literature.

Mahrs aU Clone, Iteration 1

As I’ve announced a month ago, my homebrewing project for 2020 is to develop a clone recipe for Mahrs aU. I brewed the first iteration on December 27, and here’s a quick report on how that went:

My grist was fairly simple, 2.4 kg Pilsner malt and 2.4 kg Munich I malt, both from Weyermann. I doughed in with 20 litres of water which I had treated with 6 ml of lactic acid (something something counteract local water’s hardness, I calculated this ages ago and stuck to it since, I’m terrible with water chemistry). I then conducted my preferred double decoction mash where I start with a very large thick decoction, rest it at around 70°C when heating up, then boil it and mix it back, and then pull a thin decoction, boil it, and mix it back again. The temperature steps the main mash was undergoing in this case were 39°C (dough-in temperature), 62°C and 72°C. I then moved the mash to the lauter tun, recirculated to get clear wort and then started lautering, measuring 17.6 Brix on the first runnings. I continuously sparge, and after 30 minutes, I had enough wort collected to bring it to a boil. Pre-boil gravity as determined by refractometer was 11 Brix.

After 90 minute boil, with hop additions (2019 harvest Perle, 7.2% alpha acid) at 90 minutes (32g) and 10 minutes (10g) before the end of the boil, I moved the wort the a fermenter and chilled it down to 10°C before adding two rehydrated sachets of W-34/70 yeast. Fermentation took off about 36 hours after pitching the yeast.

Things didn’t go quite as planned, as the wort’s OG turned out to be 13.3°P. My grist calculation was based on previous batches in which I employed the same mashing regime, but this time, for whatever reason, efficiency was quite a bit better than what I wanted to achieve. I’m not going to complain about it, as it’s only 0.6°P (roughly 0.002 in gravity points) higher than where I wanted to get to.

Fermentation was quite a bit slower than usual. I’m not sure why, but I may have rehydrated the dry yeast improperly, therefore slightly underpitching. Even after four weeks, fermentation did not seem quite finished. I would have waited, but two days ago, another problem came up: the seal on the fermenter’s tap was leaking. Not a whole lot, but in the tray underneath, a few hundred ml of beer had built up. Since this was just the first iteration, and things weren’t 100% right from the beginning, I decided for an emergency plan: instead of lagering properly, I just cold-crashed the beer, hoping not more would leak between Friday and today, and then bottled the beer today. With 4.4°P, I’m not 100% sure the beer had completely finished fermenting (though there wasn’t really much of a noticeable residual sweetness), but I bottled it anyway and just let it naturally carbonate over the next few weeks. To be frank, I’m not particularly happy with that, but given that things weren’t right from the beginning, it’s still an acceptable shortcut for a first iteration.

A quick taste test directly from the fermenter revealed that the beer indeed tasted remarkably close to the original Mahrs aU. While the beer was pretty clean-tasting, the hop bitterness still seemed a bit rough. My concern is that whenever this has aged a bit and smoothed out, the bitterness might not be quite high enough. Bear in mind that I based the hop additions and overall bitterness just on some very flimsy circumstantial evidence. Since then, I’ve received multiple pointers to other sources talking about the Mahrs aU parameters, such as this very helpful comment by DB who mentioned that Michael Jackson had written about aU in 1999, when it was still bittered with Northern Brewer and Hallertauer Tradition to 36 IBU, and this reply on Twitter pointing out that Ron Pattinson’s book Decoction! (seriously, you should buy it) contains OG, ABV, real extract, apparent attenuation, colour and bitterness from the year 2000 for “Mahr’s Bräu ungespundet – hefetrüb” (aka Mahrs aU), setting the bitterness at a whopping 42.5 EBU.

I’m still waiting for the bottled beer to condition and slightly mature before I’ll start a proper taste test the results of which will then be the basis for my next step. Based on the brew day itself, I will probably slightly reduce the amount of malt the next time so that I can get closer to 12.7°P in OG than the 13.3°P of the first iteration. Also depending on how the bitterness shines through, I may slightly increase the bittering hops.

I also chucked out that particular fermenter and ordered myself a 30 litre Speidel fermenter instead.

My Home-Brewing Project 2020: Cloning Mahrs aU

Possibly one of my and my wife’s favourite beers from Bamberg in Mahrs aU. It’s an ungespundetes (unbunged) pale-amber Kellerbier, meaning that it was carbonated without spunding, taking up only the amount of CO2 the liquid would do under the current temperature and atmospheric pressure, and is normally served unfiltered.

Brewing ungespundetes Bier is traditional for Bamberg, and has already been described as being particular to the city’s brewing practice in the 19th century (e.g. Das Bierbrauen in allen seinen Zweigen by Johann Muntz from 1840, p.121). It also shows in the name: “aU”, which some people call the shortest beer order in the world, is local colloquialism for “ein Ungespundetes”. The Mahr brewery in Bamberg, located in the city’s district “Wunderburg” and just opposite of Keesmann brewery, has been around since 1670, and has been owned by the Michel family since 1895. They are one of the traditional Bamberg breweries, and not just because of aU, they have a faithful followership locally and around the world.

A glass of aU, straight from the source.

If I want to brew a clone of Mahrs aU, I first need to find out about the beer’s specifications. Fortunately, I found a video from 2010 about the production of aU that contains some information: https://www.youtube.com/watch?v=Ubmm2j-2Uq4 (embedding is unfortunatey disabled, so you’ll have to click the link to view it)

From there, we can extract quite a bit of information about the beer. It’s a bottom-fermented beer, with an original gravity of 12.7°P. The grist consists of Pilsner malt and Munich malt of unknown ratios. The sole hop variety used is Hallertauer Perle with an unknown hopping schedule or bitterness. The final beer contains about 5.2% alcohol by volume and is carbonated with 4 grams per litre of CO2.

This is already quite a bit of information that we can work with and construct a recipe out of. Of course, I don’t expect the result to be perfect, so this is just a rough first outline. Further changes to this are up to the result of the first brew.

For the grist, I will start with simply 50% Pilsner malt and 50% Munich I malt. I couldn’t find anything useful about the mashing regime employed at Mahrs, so I’m simply sticking to my preferred double decoction scheme, hopefully ending up with a wort of the right OG.

For the hops, I’m sticking to just Perle. I managed to buy fresh 2019 harvest cone hops, which in my case have 7.2% alpha acid. I estimate the bitterness of aU to be roughly around 30 IBU. This is not just based on taste testing, but also on a rough bitterness scale that Mahrs provides on their website: the Helles has 3 hops, the aU has 4 hops, and the Pils has 6 hops. The following is a lot of conjecture, but bear with me: if the Helles has roughly 20 IBU and 3 hops, then 1 hop in their proprietary scale is equivalent to 6.66 IBU. If we assume the Pils to have around 40 IBU (it is rather bitter) and 6 hops, we get the same result: 1 hop is equivlaent to 6.66 IBU. In that respect, the scale seems fairly consistent. Based on this, a beer with 4 hops bitterness should be equivalent to about 27 IBU. Now I dare anyone to correctly blind-taste the difference between 27 and 30 IBU.

So for a first test brew, I decided to simply add to hop additions, one at the beginning of the boil (90 minutes) at 1.6 g/l, and a late addition just 10 minutes before the end of the boil at 0.6 g/l. This should add the desired bitterness of about 30 IBU, and leave behind some hop flavour and aroma, without being too hop-forward.

I will ferment this beer like any of my other bottom-fermented beers at 10°C, and then briefly lager it. In the beginning, I will simply use W-34/70 yeast. I do think though that Mahrs house yeast strain has quite the impact on the overall flavour of the beer. This is noticeable in direct comparisons of their aU and their Helles which I’ve conducted, and the Helles has some underlying subtle spiciness that is very present in the aU and can’t simply be explained through the malt (the Helles most likely contains no darker malts, unlike aU) or the hops (the Helles is hopped with Hallertauer Tradition and Mittelfrüh, whereas aU is all Perle). A future point in experimentation is to see whether there is any live yeast in bottles of aU which could be grown and used to ferment later batches, or whether other commercial strains show better results, in case straight-up W-34/70 doesn’t cut it.

This is my hypothesis how an aU clone could be constructed. Whether any of speculations hold true will show when the first test brew is ready to drink. My plan is to brew it with the next few days, which means it will be ready in about 6 to 8 weeks time. I’ll keep you updated here.

German Sparklers

Sparklers, little attachments to a beer engine’s nozzle that aerate the beer and produce a bigger head, are a bit of a controversy. Northerners stereotypically swear by them, Southerners despise them, etc. Personally, I think they make sense with some beers, but not so much with others. My personal hypothesis is that a lot of cask beers are brewed with the intention of being dispensed with or without a sparkler. A pint of Landlord without a thick head on top would certainly be weird, while London Pride served through a sparkler was probably one of the grossest pints I’ve ever had.

Most people think that this is probably a problem only cask beer aficionados in England face, but at least in the 19th century, lager beers in Germany and Austria directly dispensed from wooden casks were served in a similar way: besides the regular tap, a device called Mousseux-Pipe, sometimes also called Bierbrause (lit. “beer shower”), was also quite common. I’ve never seen an actual photo or illustration of one, but the descriptions of it make it sound very much like a sparkler: when beer was dispensed from a cask through the Mousseux-Pipe, it foamed up and produced a bigger, denser head.

As with every aspect of beer, the effect of this dispensing method also came under scrutiny by beer researchers. Th. Lange compared how much carbon dioxide was lost when dispensing from a regular (wooden) tap compared to dispensing from a Mousseux-Pipe, both with bunged and unbunged beer.

The total loss of CO2 when pouring bunged beer was 14.6% from a regular tap, and 22.72% from the sparkler tap. For unbunged beer, which is lower in CO2 in the first place, the loss was slightly lower: 10.27% from a regular tap, and 14.03% from a sparkler tap. (Source)

What’s also interesting is the amount of CO2 lager beers were served in the late 19th century: a regularly carbonated (bunged) beer contained 3.9 g/L (= 1.99 volumes) of CO2, a medium-bunged beer 3.457 g/L (= 1.76 volumes), while an unbunged beer contained as little as 3.097 g/L (= 1.58 volumes) of carbon dioxide. Compared to the typical carbonation of modern beer, this is fairly low: modern lager beers are often carbonated at around 5 g/L or roughly 2.5 volumes, while cask ales are carbonated lower at roughly 2.9 to 4 g/L (1.5 to 2 volumes).

So when we’re looking at the historic carbonation rates, it clearly shows that they are more in the range of what we get in modern cask ale. These historic lager beers seemed to have been more gently carbonated, making for a nicer drinking experience, something that you would find also in beers gravity-poured from wooden casks in Franconia.

Just like its modern counterpart in England, the use of Mousseux-Pipen was not uncontroversial either: in Tyrol, the use of syringes of similar devices to create artificial foam in beer was prohibited from 1854 on for sanitary reasons. A letter to the editor in a newspaper from 1871 laments the “strict non-enforcement of this edict got rid of syringes” and popularized beer showers that produced a thick and dense foam that helped defraud customers through underpouring.

Some publicans also saw sparkler taps as an issue: the wooden casks of the era were not entirely tight, so they gradually lost carbonation. Combined with a sparkler tap and the agitation when transporting, handling and tapping the casks, this led to an unacceptable amount of carbonation loss resulting in flat beer.

The organization of Viennese brewery owners even blamed assertions of beer adulterations on poor beer pouring practices: beers that tasted overly bitter were accused of using something other than hops for bitterness. Practically, beer that was poured hard and through devices like sparkler taps ended up flat, and no CO2 to soften down the hop bitterness. The Viennese brewers therefore suggested to pour beer as little as possible, and with as little devices in between. Instead of getting beer poured through a sparkler tap into a jug or large bottle, and then carried all the way home, beer should ideally be poured directly into a glass through a regular tap, and protected from sun and heat while bringing it home.

All in all, Mousseux-Pipen seemed as controversial back in the day as sparklers are in England nowadays. While I couldn’t find anything definite, I’d say the practice at the very latest died out when gravity-pouring beer from cask fell out of fashion, and more modern top-pressure-based dispensing methods became popular. And frankly, in the narrow context of gravity-poured lager beers, I don’t really see the need for it, as I’ve never seen such a beer freshly poured from a cask suffering from any foam issues, while still having a gentle carbonation that makes it easy to drink. Maybe brewers have become more knowledgeable about brewing beer with greater foam stability, or the slightly higher carbonation of modern lager beer is making a difference, or maybe the higher quality of modern “wooden” casks (most of which are metal-lined nowadays) means less CO2 leakage and a better retention in carbonation. In any case, a properly poured beer directly from a cask, with a nice thick head on top, makes for a great presentation, and I crave one now.