The challenge of brewing a great lager

ken writes:

Why is it so difficult for most microbreweries to brew a nice lager? Some ideas

  • Microbrewers don’t always like and appreciate lager, so they aren’t motivated to get it right.
  • Microbreweries strive to be flexible and have a wide range of different beers, which means there is some pressure to use labour-saving and simplifying active dry yeast, which doesn’t necessarily give the finest tasting lager.
  • Microbreweries are typically young businesses and capital-constrained businesses, so they cannot afford to tie up tank farm capacity with long vessel residence times. The traditional rule of thumb (according to Wolfgang Kunze) is 1 week of fermenting and 1 week of conditioning for every degree Plato. 24 weeks for a single batch! I don’t think so.
  • Microbreweries tend to be built on the English model, not the German one (because it’s cheaper), so they have difficulty producing a suitable wort.


Here are some tips for making a better lager.

  • Start with very good malt. Use a well-modified ale malt and accept that the lager will have a slightly darker colour. This is no big deal. There are superb ale-coloured lagers e.g. Pilsner Urquelle (totally different process, mind you). The higher kilning temperatures of ale malt mean there will be less DMS (dimethylsulphide) precursor in the malt.
  • Pitch massive quantities of yeast. Either grow it up first or pitch twice the recommended amounts. This will give you good attenuation, and will allow you to get a vigorous and timely fermentation at lower temperatures. Proper lager fermentation temperatures are really low: The old-school cold fermentation recommended by Narziß starts at 6˚C and allows the fermentation to rise as high as 8˚C! 12˚C is the absolute highest temperature you should allow. Don’t leave the beer on the yeast longer than you have to. That’s bad for the head, especially with lots of yeast.
  • Use shallow open fermenters. These promote the purging and washing away of volatile sulphur aromas as well as the rapid settling of yeast. (Shallow fermenters also tend to reduce attenuation so plan for this in the mashing profile and with yeast choice.
  • Use measures to promote the coagulation and precipitation of protein in the brewhouse, for example ensuring boil pH is 5.1-5.2 (suggested by Kunze), boiling without hops initially, using tannic acid additions to coagulate proteins which aren’t  otherwise coagulated by heat, using Irish moss or other kettle finings, and treating kettle wort with gypsum again. Run the wort into the whirlpool gently to avoid breaking up large flocs. Allow a longer wait in the whirlpool to give more settling time and to allow some hot wort oxidation will also promote clarity in the final product.
  • Use traditional hop varieties. It should look like beer, smell like beer, and above all taste like beer.
  • Boil away at least 10% evaporation.

How much actual lagering time the lager needs depends on how successful the measures to promote clarity and aroma in the brewhouse. The traditional purpose of lagering beer, according to De Clerck, is mostly clarification, carbonation and the removal of green beer aromas. Carbonation is taken care of in most microbreweries by forced carbonation with CO2. Clarification can be sped up by filtering and/or fining. This is what used to take so long because the protein-polyphenol complexes that cause chill haze are extremely small and settle extremely slowly. Tannic acid and colloidal silica treatments can encourage their precipitation, agglomeration and settling. Shallow tanks speed settling time because there is less distance for particles to fall. The removal of green beer flavour is mostly accelerated by doing as much as possible to avoid the sulphurous flavours in the first place. Look at the choice of malt and the choice of yeast strain and don’t ferment the beer under top pressure.


CAMRA is right to retain its focus on cask ale.

Ken writes:

Pete Brown recently set out his reasons for being disappointed in CAMRA’s decision, taken at an AGM, to retain its focus on cask beer (and cider and perry) rather than all beer (and cider and perry). The text of the special resolution that fell short of the 75% majority required to be accepted was “2(e) to act as the voice and represent the interests of all pub- goers and beer, cider and perry drinkers;”, with only 72.6% in favour. The wording of the text doesn’t seem objectionable on the face of it, but it neglects to restrict the advocacy to drinkers of real ale, real cider, and real perry, so it was understood to involve broadening CAMRA’s remit beyond real ale.


The proposed change was part of a modernising project. CAMRA arose in opposition to mass-produced, sterile filtered, light-bodied and lightly hopped, very cold, very fizzy, virtually ubiquitous and indistinguishable lager. But in the current market there are lots of flavoursome and appealing beers that don’t meet CAMRA’s definition of real ale, that is beer containing live yeast and conditioned (continuing to ferment) in the container it’s dispensed from. In other words, an up-to-date CAMRA should support good beer in general and certainly all good beer from small independent microbreweries and not get fixated on the matter of beer dispense. It’s absurd to think that a batch of beer could be real ale in the tank at the brewery (if you tasted it there), then split and packaged separately into kegs, which are dispensed with external CO2 and are not real ale, and casks, which are dispensed with a hand pump and are. It’s the same beer.


But the absurdity is not absurd!

CAMRA makes an honourable exception for bottle-conditioned beers, and for unfiltered unpasteurised cider and perry, but the focus and animating principle behind CAMRA has always been cask dispense. ‘Real Ale’ is really a kind of metonomy or shorthand way of referring not simply to the liquid but to a whole complicated set-up involving brewers, publicans and of course pub-goers. That is why CAMRA’s campaigns against the beer-tie and for community pubs were a natural part of its remit. You cannot have ‘real ale’ without pubs, not really. And bottle-conditioned beers don’t cut it.

‘Real Ale’ is an instance of metonomy, specifically synecdoche, referring to a whole through referring to a part, just like saying ‘King Joffrey can muster a thousand spears’ when you mean he can muster a thousand soldiers. ‘Real ale’ really means ‘cask ale’ and it really means the liquid and the apparatus that dispenses it and the breweries and pubs that sustain it.

Cask ale as an institution really is something different from the rest of the “craft beer” thing. Here in Ireland we have a small but rapidly growing craft beer scene and it’s part of the same international cultural movement that has seen people tire of pretty generic and characterless lager brewed by multinationals. Craft beer in Ireland, NZ, Australia, Canada and the US has plenty of good examples (and also some bad). But it’s not really the same as the cask ale thing in the UK.

Cask ale is almost like a style of beer to itself, except that its defined by the processes of production and dispense rather than by the ingredients. When the ‘same’ beer is served on  cask and on keg, does it taste the same? Is the experience really the same? Of course not. The cask beer is a handful of degrees warmer, and the beer has less carbonation, and the beer may have started to oxidise. These things all influence the experience. The keg version may have a haze lacking in the cask version. But really, the ‘same beer’ shouldn’t be served on cask and in keg. A good brewer will optimise recipes for their method of dispense. Especially the amount of carbonation in the beer is not a separate thing from the beer. Volumes of CO2 in solution is a recipe choice just as much as the choice between Saaz hops and Centennial hops, or between Nottingham yeast and W34/70.

Because cask ale is an institution that involves pubs as much as it involves breweries, it’s really hard if not impossible to introduce it into a community that doesn’t have it. There aren’t the customers to sustain the short shelf life of cask beers and the brewery’s reputation is in the hands of publicans who may or may not have the training to ensure the beer reaches the public in a fit state. Too many risks to make the economics work out.  It’s almost more important that CAMRA focusses specifically on the dispense side of what makes cask ale what it is because breweries could change from cask production to keg production (and vice versa) pretty easily, whereas cask cellarmanship is a particular set of practices and know-how specific to cask beer.

If we see cask ale as an institution, and as something like a certain style of beer, and something that could die out and would be near impossible to resurrect if it did die out, then it seems OK to have a consumer group that retains that focus. Craft beer in general is a thoroughly good thing, but it would be a very real loss to beer culture in the UK if it lost cask beer.



Hazed and confused

Ken writes:


I started writing this post a year ago when I was about six months into a new job. We had  dreadful problems filtering beer for sale and very slow lauter times. I didn’t get round to finishing the post then, but we turned the problems around so I thought it might be helpful to anyone in a similar predicament to hear what we did.

The description of the problem.

The problem was basically two fold: It took forever to filter beer to remove chill haze, and it took forever to lauter the wort. Chill haze is a mild form of turbidity that forms when different compounds are precipitated out of the beer by cold temperatures and adhere together forming tiny particles. We had to filter one or two beers we brewed on contract and our own lager. A three thousand litre batch would take all day to filter despite the fact that the filter was rated for 3000 litres per hour. Some of the time was just setting the filter up and cleaning it down at the beginning and end of the work, but the time in the middle was dire. “lautering” is the process of separating the husks and other undissolved matter from the sweet wort after mashing. When it came to lautering, if we got the wort out in 3 to 3.5 hours we were slapping each other on the back and giving each other high fives. We were staggering our  starts because it took about 10.5 hours for a single brew. Everyone was exhausted.


Kettle and lauter tun


Lauter times

They say problems in the tank farm usually have their origin in problems in the brewhouse so I’ll talk about that first.

Although we had a really top notch 30hl Kaspar-Schulz brewhouse, we were running it on a manual basis because the automation program hadn’t been installed. The brewery was purchased second hand and the original automation program couldn’t be installed when the brewery was put it in. The local electricians weren’t up to the job and many of the wires connecting the sensors to the plc were connected wrong. The plant was capable of excellent lauter performance, but we weren’t using it correctly. We subsequently got our lauter run off time down to less than 90 minutes, so that shows what it was capable of.

Inside the lauter tun


We did a number of things to try to improve lauter performance. We opened up the mill settings to produce a coarser crush in the hope that this would provide a better filter bed. We tightened the mill settings to produce a finer crush (because opening the mill hadn’t helped—maybe unmodified gelatinised starch adhering to the husk was settling at the bottom of the tun and forming a layer of impermeable gunk).

We seemed to run the first worts off too quickly so we started slowing that right down. We would run off only with gravity and then throttle the flow in addition to that. But still it didn’t really help. We would eventually have to underlet and smash up the grainbed with the rakes and then recirculate for ages, which would compact the bed again, or let cloudy wort through to the kettle.

The bed was always pretty dense and settled like a slab on the base of the lauter tun. It seemed like every mash was a stuck mash.

The beginning of the solution was changing how we operated the mashtun/kettle. The kettle had paddles in the bottom to prevent the mash burning on to the base of the kettle during heating up between the various rests. We used the paddles at full speed when we mashed in to ensure there were no dough balls and to obtain and even heat throughout and full-speed while we were heating, but we continued to paddle at half-speed during the rests/stands. When we stopped doing this, the mash remained more buoyant when we transferred it to the lauter tun. It still settled on the base of the tun, but it had a certain buoyancy that had been missing.

The next change was in raking behaviour. We had played around loads with the rakes adjusting the height at which they operate and their speed but couldn’t settle on the right regime. Eventually we hit on it. We completely ignored the height adjustment and left the rakes at the bottom of the tun. The reason for this was that plenty of lauter tuns are actually designed with rakes set at a fixed height, so the height at which they operate couldn’t be very significant. The speed adjustment was important. We set the speed to one revolution every two minutes. This wasn’t enough by itself. The break-through was stopping the run off during raking. Running off during raking must pull fine particles lower and lower into the bed. Raking by itself served to loosen the bed without sending the fine particles to the base of the tun.

Once we discovered this, and obviously it would have been built into the original automation programme, we could speed up running off the first worts. We would run the first worts off in 25 minutes or so, add some sparge water and then rake to loosen the bed again, and begin running off after the raking had restored the pressure difference across the bed, as measured by two sightglass tubes, to near equality. I’m convinced here that the critical development was not running off while we were raking.

It all seems so simple now, but it took us a long time to identify the decisive measures while we were struggling because there were so many possible things that could have played a part. Different malt bills were certainly relevant, with the lighter beers being easier to manage than the darker ones. There seemed to be recipes that were particularly bad and we experimented with using malts from different manufacturers and even changing the recipe completely (leaving only the final colour the same). It took such a long time to get feedback regarding any change. Raking in the wrong way can do lots of damage to the lauter performance, but you don’t discover this until the damage is already done.

Chill Haze filtration

There can be a number of reasons why you may have trouble filtering beer. We had a filter skid set up with a 3 micron, 1 micron and 0.5micron sequence of ever tighter filter cartridges to yield a virtually sterile product. The tighter cartridges could be bypassed if we only wanted to filter out yeast. The 3.0 micron was only nominally rated, meaning that some particles smaller than 3.0microns could pass the filter (just not very many). The 1.0 micron and 0.5 micron cartridges were absolute ratings (nothing smaller than the rated size should be able to pass through).

We occasionally had problems with the 3.0 micron filter but generally did not. If we fined the beer and moved it into a dish-bottomed conditioning tank before filtering, then we had no problems. Filtering straight out of a CCV caused problems when a large plug of yeast would dislodge itself and get sucked into the filter housing and then block the filter cartridge immediately.

The 1.0 filter was there to protect the 0.5 micron filter. It did its job very well and we hardly ever had to change the 0.5 micron cartridges. The 1.0 micron filter always blocked. We wondered if it was yeast passing the 3.0 micron filter so we put 2.0 micron cartridges in before the 1.0 micron to see if that would make a difference, but it didn’t help. So the haze creating particles were smaller than 2 microns but bigger than 1.

They say problems in the tank farm are almost always traceable back to problems in the brewhouse and it sort of was that way for us too. We noticed that certain recipes never gave us any trouble filtering so we looked what they had in common and they all involved a low-mashing in temperature and a protein rest. As a result of this, we introduced a number of steps to reduce the amount of protein in the finished beer. We mashed in at 45˚C (to allow some beta-glucanase activity) and then heated through to the saccharification temperature at 62˚C, and then a starch rest at 72˚C, and then mash out temperature of 78˚C. This didn’t involve a protein rest as such, but gave the proteases scope to work. (We were mindful that we did not want to degrade the proteins responsible for beer foam too much as the boss had a very strong preference for good foam on beer). We also brought the mash pH more under control. The best lauter performance seemed to be at around pH 5.4. The feeling was that if the lautering goes easily that will be better for filtering as well because the wort will already be cleaner. We boiled for 15 minutes prior to adding hops to get lots of foaming in the kettle. We slightly increased the amount of kettle finings we used and we changed the way we transferred the kettle contents to the whirlpool to avoid breaking up large protein flocs. Finally, we started using a colloidal silica solution in the conditioning tank when the beer was cold. of these measures, I believe the protein rest/low mash in temperature made the biggest difference.

There were a couple of cul de sacs. Adding Brewtan B, a solution of tannic acid, to the mash or to the boil did not seem to help much. It could be however that it had a positive effect but for some unrelated reason this was cancelled out by something else. You have to remember that we were still producing beer at a very hectic pace throughout this time and there was a gap between brewdays and filtering days and so day-to-day demands on our attention meant it wasn’t always easy to relate what we were seeing in one part of the brewery to what had happened a couple of weeks ago somewhere else. We had loads of problems with our tank farm cooling so we always seemed to be lurching from one problem to another. That got sorted in the end. Buíochas le Dia.


Happy Ending

It’s incredibly satisfying when you feel you have solved a problem in the brewery. It’s such a complex operation and so interconnected that you can never really take an off-the-shelf solution from what you’ve read or found elsewhere. I was lucky to have a number of really quite eminent brewing scientist friends who could be called on to help me understand the problems but no one was able to just walk in and diagnose and treat the problem straight-away. You have to know the brewery equipment fairly intimately. Even purely physical things like vessel dimensions and materials, agitator speeds, pump types, pipework, heating capacity can make a difference, to say nothing of the chemistry of the different processes. But it all serves to make you feel even better when you do finally get it right.



Hot Wort Oxidation

Ken writes:


One of the nice things about craft beer has been how the drive for novelty has ironically lead to brewers revisiting old beer styles and practices that went out of favour when the big breweries decided to focus on super light lager.

I’ve been reading old brewing textbooks recently (because they’re out of copyright and therefore affordable) and it’s fascinating to read about some of the practices they used.

Hot Wort Oxidation (or hot side aeration) is mentioned in both A Textbook of the Science of Brewing (Edward R Moritz and George H Morris, 1891) and A Textbook on Brewing (Jean De Clerck, 1958) as a process step in its own right.

The benefits of hot wort oxidation according to de Clerck are:

  • increasing the colour of the wort
  • reduced bitterness
  • promotes clarification

Moritz and Morris explain the action of oxygen on hot wort as follows.

Oxygen taken up by hot wort plays a different part. It is not mechanically dissolved, but is chemically fixed, entering (as Pasteur shows) into some form of combination with the hop resins. It is this form of aeration that plays so important a part in the natural clarification of beer, or in its ready clarification by isinglass finings. When resins are modified by chemically fixed oxygen, they conglomerate into particles of greater density: these sink easily to the bottom of the storing vessel, forming a compact sediment, and leaving the supernatant beer bright. When, however, for some reason or other, the aeration of the hot wort is incomplete, the resinous substances, instead of conglomerating and acquiring the density necessary for their rapid deposition, remain suspended in the finished beer in a very fine state, and in that condition they are equally unready to deposit naturally or to yield to the action of finings. (E. Moritz and G. Morris, A Textbook of the Science of brewing, 1891, p. 272)

Neither textbook speaks of hot wort oxidation as a replacement for or alternative to cold side aeration (mechanically dissolved oxygen), but a complementary process step to promote clarity of the finished beer.

Hot side aeration happens naturally in coolships during the first minutes after filling the vessel owing to the large surface area. However it takes place only while the wort is close to boiling temperature. After that point the slow cool down to yeast pitching temperature  increases the chance of infection so the authors recommend switching to plate heat exchangers before the temperatures favourable to bacteria are reached (150˚-130˚F Moritz and Morris, p 269; 70˚-60˚C de Clerck p.334).

Given that deliberately aerating wort to encourage oxidation goes against what we’ve been taught for ages, I don’t see anyone ordering a coolship to try it out (unless they hope to get spontaneous fermentations as well). But in many breweries it would be easy and inexpensive to modify the pipework slightly to accommodate to create a venturi-effect just before the whirlpool inlet to suck in a steady stream of ambient air.

I’m not ready to do even that much, but I might try it on my pilot brews for the next while to see if I notice an improvement in beer clarity (or any problems with oxidisation off-flavours!) It might be a technique that is better suited to English and Belgian styles.

The Wife’s Lament

As part of a module I’m teaching this term I’m getting the students to write creative pieces prompted by Old English texts. I thought I’d have a try at doing one myself, so here’s something based (loosely) on the Old English poem ‘The Wife’s Lament’. The length limit for the exercise was 1500 words and I’ve come in just under.


Today she’s sad. I find her easier to cope with when she’s angry, to be honest. Then I rise up on the boil of her rage, up the dark steps like a messenger from the netherworld.

“Why did you pick this horrible basement flat?” I ask her.

“He told me to piss off back to Grove Road,” she says, “So I did. It’s all I can afford now anyway.” She’s sad today.

She misses him, after all these years, and I suppose I have to respect that, though I find it hard to understand. He was such an utter prick to her.

“We were soul mates,” she tells me. “Everybody saw the talent, the outrageousness, the way he could dominate a room, but I saw the sadness in him. The need. He was just a little boy really, always needing a woman to care for him.”

Of course this need for a woman’s care extended to sleeping with someone else the night she gave birth to his baby. But one has to try to understand the human psyche in all its rich complexity.

Continue reading “The Wife’s Lament”


Dot writes:

fiction isn’t happening for me and hasn’t been for a while. It’s not that I don’t have ideas, just that none of them go anywhere. They are sedentary ideas, reluctant to venture into the January wet, slumped in front of their computers. Is it worth getting any of these moving?

Quiche Lorraine

Quiche Lorraine is a heroine who works as a canteen lady at a tech firm. Once, helping to unload the Tescos delivery at the back of the office block, she spotted a nefarious character seeking to enter without a lanyard. Thinking quickly, she threw a quiche in his face and he gave up the attempt. Thus her name. Few people know how she got it but the ones who do recognise it’s a badge of honour.


The problem with Sean was that he had no real interest in anything anybody else said or did. He was very generous, very kind – he’d buy you dinner, or a jumper you liked, or tickets to a film he’d just seen and wanted to tell you about. He was popular with small children because he knew a few magic tricks and was always delighted to show them off. He liked to tell people things he knew, such as the way Teflon pans are made or how events were misrepresented in the currently popular TV history drama. However, if you knew more about that particular historical period than he did he was never going to find out. He would never stop talking for long enough for you to mention it.

So Louisa thought, sourly. The shine had long worn off him as far as she was concerned. Or, rather, she’d realised he was the sort of bright light that only made everything else seem darker – a localised dazzle that didn’t illuminate. And she herself was especially cast into shade, practically invisible, in fact – Sean’s sister and, thanks to personal setbacks, currently, reluctantly, his housemate – appearing briefly on the edge of his sociable evenings to boil a kettle and disappear again. But there are things you can do in the dark.


The girl under the lamp-post smiled happily. She knew she had done well. Duncan had only managed to get a bollard. Kelly was pretending a wheelie-bin was an achievement but, really, it was a flimsy thing and not even fixed to the ground. Look at her tying herself on with pathetic thoroughness, as though you could solve everything with a sufficiently complicated knot. Sometimes it didn’t matter how hard you worked or how clever you were; it was just about where you were standing. The girl under the lamp-post pushed against the belt that strapped her to it, to check it would hold firm.


I Fall Apart

Here are two versions of a song.

This is the one I heard first. It’s sweet and melodic and sad. It immediately became a song I needed to hear many times.

As it happens, it’s a cover, and here is the original. On first listening I liked it far less.

Probably all people who properly keep up with current music have heard the Post Malone version and not necessarily the Flor version, but I tend to come at everything sideways – in this case from letting Spotify play on after the last Haim album, which led me to Flor’s single ‘Guarded’, and some time later to investigating them further. Their recent album is a feast of irresistibly tuneful indie pop and I thoroughly recommend it. Also the singer, Zach Grace, is as cute as a bag of kittens.

But back to Post Malone. The original version of the song definitely grew on me. I post it here partly just to share the song in both renditions, but partly because it’s a case study in how trying to think about things can change my enjoyment or aesthetic experience of them. When I first heard Post Malone I thought “oh, the vocal is a bit forced, when Zach Grace has such a sweet, expressive voice; and the tempo is slower and it seems draggy; and where’s that great bass line I was enjoying; and I don’t like the hip-hop instrumentation as much as those clear and pearly guitar parts” (I was going, of course, from the cover to the original). However, the more agonised and rough delivery of the original version, and that tough guy aesthetic in the general musical style, makes sense with the lyric. “Oh, I fall apart, down to my core” – but he’s trying to self-medicate after his break-up – “harder than the liquor I pour” – and he’s resorting to misogyny in a crap, macho way that just confirms what a mess he is – “devil in the form of a whore”. When Zach Grace sings that line it sounds a bit rougher than the rest but it’s hard to believe he might mean it. When Post Malone sings it you see the ugliness in sadness, how falling apart means feeling and behaving like shit.

That all sounds very intellectually pleasing, doesn’t it? I should prefer the Post Malone version now, as being more insightful or authentic or something. Indeed, thinking through the song’s themes did go hand in hand with acclimatizing to Post Malone’s sound-world. But Flor’s sound is so lovely; and really I’d rather listen to them.