Beer in the DDR (part 4)

Still more of my DDR beer talk slides.

Kicking off with a nice drawing of a Steinecker brew house. Though I'm not sure if any brewery had enough hard currency to buy such a system. Most brewing equipment was manufactured in the DDR. There were some occasions, though, when some was imported from West Germany. Usually, because there wasn't the capacity to produce it in the DDR.

We then continue with boiling and hopping rates. Not much to say about that. Obviously, beers like Pilsner were amongst the most heavily hopped.  Porter was the beer which received the most hops. Which made sense, as it was both very strong and  a beer.

Fermentation follows. As most beers were bottom-fermented, the temperature was pretty low.

Lagering was mostly in horizontal tanks. Though from the 1980s some of the larger breweries started to install conical fermenters where beer was both fermented and lagered. Full-strength beers were lagered for three to six 

The shelf-life of bottled beers was mostly shorter than the lagering time. Just 8 days for Helles.I remember Eisenach Helles not being particularly stable. You wouldn't want top walk back from the shops too slowly in case it had gone off before you got hoe,.

We finish by starting to look at DDR beer styles. 

 

1980 DDR lagering times

You may have noticed that the 1980 version of TGL 7764 includes more information than the one from 1960. One of those extra bits of information is lagering times. 

It's a topic close to my heart. On one tour of Franconia I asked about lagering times at every brewery I visited. I think the shortest time was 6 weeks and the longest 16 weeks.

Turning to the DDR, the shortest time was given to Aubi, non-alcoholic beer. Just 3 days minimum. Though I'm surprised they bothered lagering it at all. Next shortest were the low-alcohol beers Eifachbier Dunkel and  Doppel-KarameI. Which makes sense.

Lagering time is one of the distinguishing factors between Edel-Bräu Hell and standard Hell. The former spending twice as long lagering. We see exactly the same difference between the posh Pilsners and the standard Deutsches Pilsner.

Rather surprisingly, pale and dark Bock only got a maximum of 30 days. Which seems odd. Usually strong beers get the longest lagering.

1980 DDR lagering times
Type	Standard time days	min  time days
Aubi	6	3
Dunkel (Einfachbier)	8	5
Weißbier	30	25
Extra	40	25
Hell	20	12
Edel-Bräu Hell	40	25
Dunkel (Vollbier)	20	12
Doppel-KarameIbier	8	5
Schwarzbier	20	12
Deutsches Pilsner	25	15
Diabetiker-Pils	50	30
Deutsches Pilsator	50	30
Deutsches Pilsner Spezial	50	30
Märzen	50	30
Weizenbier	20	8
Weißer Bock or Bockbier Hell	30	18
Dunkler Bock or Bockbier Dunkel	30	18
Deutscher Porter	40	25
Source:
1980 TGL 7764, page 8.

I've just noticed that I almost all the examples of Edel-Bräu Hell labels I have are pretty much identical, save for the brewery name. The label for this type seems to have been standard everywhere.

Lagered Beer.

It's funny sometimes the places you come across information. Stuff you've been looking for, but were unable to find.

Oh, we're back with Heineken again, by the way. Just in case you were wondering.

Finding stuff in unexpected place is why it's always a good idea to exhaust every possible source. Despite reading through lots of very detailed Heineken brewing records, I'd been able to unearth only patchy information about their lagering regime. Now I think I've tracked it down. Not in any Heineken document, but in a newspaper article.

An article that isn't even about the Amsterdam or Rotterdam brewery. Instead it's discussing the Heineken plant in modern day Indonesia.

"Lagered Beer.
The “classic” system introduced in India.
These days, the management of N.V. Heineken's Ned.-Indische Bierbrouwerij Mij., more popularly known as the Java beer brewery in Soerabaja, received a number of invitees and the press to view its new yeast and lager cellar department.

Mr. De Man set out in a short speech the purpose of the meeting. The Java breweries follow a system known as Nathan system. It consists of the beer fermenting and fermenting in the same tank. That setup is economical and good. It can be used to market cheap beers that are of excellent quality. A great success has been achieved and these breweries gradually reached their maximum capacity.

However, many consumers have a preference for lager, according to the classic system. And in connection with this, the brewery will now also lager beer.

The group was then shown around and they first visited the fermentation plant. From here the split in processing of the beers continues. One saw the Nathan tanks where the Java beer ferments and matures, after which the lager system was viewed. To this end, they came to a location where the fermentation vessels are set up at a temperature of approximately 5 degrees Celsius. Glass discs allowed to follow the fermentation process. When the beer has been exposed to this operation for about nine or ten days, it goes down into the lagering tanks. It stays here for three months to get its fine and aromatic taste. It lies in large tanks at a temperature of 0.5 degrees C. Each of these tanks contains 250 H.L.

It should also be noted that a specialty in the field of lagered beers, Dr. Mendlik, who previously worked as leader of the brewing laboratory of Heineken's Brewery in Rotterdam, came especially to Soerabaja to supervise and direct the preparation of the new lagered beers."
De locomotief 17-09-1937, page 4. 

I had been wondering what the difference was between Java beer and Heineken. Now I know. The former wasn't lagered.

As they'd brought out Dr. Mendlik from Rotterdam to set up their lager cellar, I think it's safe to assume that the procedure on Java was the same as back home in Holland.

Nine to ten days primary fermentation matches what went on in Rotterdam. So I'm guessing that was also followed by 3 months lagering at 0.5º C. Which is pretty much what I had expected. Nice to have confirmation, mind.

Something other than Heineken

Only kidding. Of course it's more Heineken stuff. Lots of crumbs of knowledge for me to peck away at.

Lagering times is today's topic. Did I mention before that there wasn't much about them in the records? That's not totally true. There are a few details and dates. Annoyingly, no temperatures are given. My guess us that the lagering tanks would have been filled with the wort at the temperature where fermentation ended. That is 5º-6º C. Then slowly cooled to around freezing.

The pattern is fill the tank, leave it open for a few days, seal it up and finally let the pressure increase. That pressure coming from the continued fermentation while lagering. Fermentation must have occurred as the eventual FG is a good bit lower than at the end of primary fermentation. All, with the exception of Export Pils, lost more than 2º Plato during secondary fermentation.

Is lagering really a secondary fermentation? I suspect not, technically. As it's really a continuation of primary. Who gives a toss about that, really? I've certainly more worthwhile quibbles to waste my time on.

Yet another table showing that fall in gravity I mentioned a short while ago.

Heineken 1935 secondary fermentation
Beer	Racking gravity Plato	FG Plato	Fall Plato
Münchener	6.4	4.0	2.4
Pils	6	3.4	2.6
Export Pils	4.5	2.8	1.7
Bok	8.2	5.6	2.6
Source:
Heineken Brouwjournalen van de proefziederij, 1935 - 1957 held at the Amsterdamse Stadtsarchief, document number 1785-1792.

The lagering times are pretty reasonable. Around 10 weeks for the Piseners and for Münchener more than 17 weeks. Just a shame that there are no examples of the two Lagerbiers. I'd love to know how long they were lagereed.

That's enough fun for today. I've some more numbers that need fiddling with. Though,  as it's not raining, I may nip out for a quick walk and read of Private Eye. That night happen to take me past Ton Overmars. Where I may as well check if they've refilled the shelf with Abt.

Pilsener 11th Jul 1935 Lagering
Step	Date
Filled	20th July
Sealed	24th July
Pressurised	29th July
Tapped	30th Sept
Tasted	26th Oct
Total days	72
Source:
Heineken Brouwjournalen van de proefziederij, 1935 - 1957 held at the Amsterdamse Stadtsarchief, document number 1785-1792, page 20.

Export Pils 18th Jul 1935 Lagering
Step	Date
Filled	26th July
Sealed	28th July
Pressurised	5th Aug
Tapped	1st Oct
Tasted	26th Oct
Total days	67
Source:
Heineken Brouwjournalen van de proefziederij, 1935 - 1957 held at the Amsterdamse Stadtsarchief, document number 1785-1792, page 20.

Münchener 2nd Jul 1935 Lagering
Step	Date
Filled	10th July
Sealed	11th July
Pressurised	15th July
Tapped	9th Dec
Tasted	9th Dec
total days	122
Source:
Heineken Brouwjournalen van de proefziederij, 1935 - 1957 held at the Amsterdamse Stadtsarchief, document number 1785-1792, page 11.

The Storage of Beer and Ale (part four)

We've now arrived at the section which specifically deals with the storage. What fun. Though I have to admit to not completely understanding some of it.

"Lager beer cannot be kept at too low a temperature, and as it is inadvisable to rack it from the casks where it is once lagered until it is ready for storage, great care should be taken to eliminate, as far as possible before storing it, all elements that are likely to result in its deterioration."
Holmes' Brewing Trade Gazette - Friday 01 September 1882, page 12.

The first phrase is anmiguous. Does it mean that it's impossible to store Lager at too low a temperature or that you shouldn't store Lager at too low a temperature. I think it's the latter. To be honest, I'm not sure whayt the second phrase means either. Surely the lagering would be the storage. Surely no-one lagered a beer then stored it afterwards?

The next part is more understandable.

"The secondary fermentation must be as nearly as possible concluded and the beer racked into the lager vats with great care, so as to take as little yeast and sediment as possible with it. It must be fined before storing in the usual manner. The use of a bunging apparatus for the control and observation of the development of the carbonic-acid gas, is now recognised as absolutely necessary in a well-appointed lager cellar Even when successfully stored, the brewer's vigilance should not cease and he must be on the look-out for internal changes that will sometimes occur inexplicably. As soon as any abnormal condition is recognised, the beer should be racked off for sale at once and no attempt made to keep it, on the supposition that it will come round, or that it can be fixed afterwards."
Holmes' Brewing Trade Gazette - Friday 01 September 1882, page 12.

It makes sense that you'd want to leave most of the lees behind in the fermentation vessel. Though obviously not all of the yeast, as some fermentation still needed to occur to condition the beer.

Though the mention of "bunging apparatus" has me wondering this was some sort of artificial carbonation. Or was it simply some kind of regulator to allow control of the CO2 pressure inside the lagering vessel?

Just one more part to go.

German brewing in the 1970’s – fermentation (part two)

What’s the best fermentation system? Who hasn’t asked themselves that while soaking in the bath or bobbing along to work on the bus, some grey winters day?

You’re in luck, because Kieninger is going to tell us. Or at least give us his opinion. He worked at Weihenstephan, so he must be right, musn’t he?

“Table XII also shows the most simple and effective method for the fermentation and maturation of lager beers of high quality in the light of modern knowledge. Primary fermentation is carried out in closed vessels, so that it is possible to collect the carbon dioxide and any required temperature may be applied. After reduction of diacetyl the green beer is cooled by plate coolers to a temperature of 0°C and after remaining at this temperature for 2-3 weeks for stabilization it is carbonated and filtered. The only analytical controls required are diacetyl and carbon dioxide and the carbon dioxide content may be controlled by in-line instrumentation.”
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, page 76.

Lager in just 28 days. I’m not sure he’s convinced me about that. I’m sure it’s a cost-efficient way of brewing. But what about the flavour of the beer? That doesn’t get a look in. Notice that it’s not even taken into consideration.

The best Lagers I’ve had I mostly knew were open-fermented, lagered for months rather than weeks and were naturally carbonated.

I’m going to repeat that table, because it’s a while since the last post in this series:

TABLE XII. Comparison of Fermentation and Maturation Systems.
Method	Primary fermentation	Transfer	Lagering
Classical	7 days at 9°C	Beer with 3-5% residual extract cooled to 4°C	35-50 days with temperature reducing from 3° to 0°C
Using Kräusen	7 days at 9º-10°C	Beer with 2% residual extract cooled to 4°C. 10-12% Krausen with 8% residual extract added	14-28 days with temperature reducing from 4° to 0°C
Under pressure at high temperature (Champagne Wheat Beer)	3 days at 16°C or 4 days at 14°C under pressure	Beer with 2% residual extract 2.0 bar pressure cooled to 0°C	7-14 days stabilization at 0°C
Modern development	7 days at 12-14°C with CO2 collection	Attenuated beer carbonated and cooled to 0°C	14-21 days stabilisation at 0°C and final carbonation

This next bit is interesting, even though it slightly baffles me:

“Fig. 2 illustrates the relationship between the time necessary to reduce diacetyl content to a value of 0.1 mg/litre and maturation temperature. At a temperature of 30°C, 48 hours are sufficient to reduce the diacetyl content to <0.1 mg/litre without addition of Kräusen but, at 8.5°C, eighteen days are necessary to reduce the diacetyl content to the same value. The addition of Kräusen also allows a reduction of diacetyl at higher temperatures, but additional 2-acetolactate is formed during secondary fermentation, so that a new time-consuming reduction phase is necessary.”

Fig. 2. Behaviour of 2-acetolactate (as diacetyl) during different maturation conditions following primary fermentation at 8.5°C. Curve A = maturation at 8.5°C with kräusen, B = 85°C without kräusen, C = 15°C with kräusen, D = 20°C with kräusen, E = 30°C with kräusen, F = 30°C without kräusen.
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, page 76.

Oh, I get it. You can break down diacetyl at a higher temperature if you kräusen, the fermentation of the kräusen creates more diacetyl. And that also needs to be broken down. Sounds like you need to add more kräusen then. Only joking. But what is he recommending ? I’m confused.

“The development of isoamyl alcohol during primary fermentation at different temperatures with and without pressure is shown in Fig. 3. Isoamyl alcohol content increases

Fig. 3. Iso-amyl alcohol content during primary fermentation in relation to temperature and pressure. Curve A = fermentation at 20ºC, B = 20°C with pressure, C = 16°C, D= 16°C with pressure, E = 12°C. F = 12°C with pressure, G = classical fermentation at 8-S°C.

with increasing temperature but the use of pressure results in a decrease of about 5 % at any given temperature.”
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, page 77.

This one has totally lost me. Be glad for an explanation by any brewing technicians out there.

Just looked up isoamyl alcohol on this wonderful new thing they have called the internet. A higher alcohol . . . . that tastes like banana. I get why Kieninger is so interested in it, being a brewer of Weissbier.

Still one more bit to go. Where fermentation systems are compared.

German brewing in the 1970’s – fermentation

We’re finally getting to the vaguely interesting bits of this article. Though obviously that’s interesting only in a relative sense.

Let’s dive right in with an explanation of the classic German method of fermentation: open, without artificial fermentation

“Technology of Fermentation and Maturation
It has been known for a long time in Germany that raising the carbon dioxide content from, for example, 0.30% (w/w) to 0.50% (w/w) by artificial carbonation causes no problems. Most breweries still use open fermentors and are unable to re-use the fermentor carbon dioxide, but the German beer laws demand that carbonation of beers is effected only with the carbon dioxide evolved during fermentation of the same brew and so-closed fermentors are necessary when beer is produced by non-conventional methods requiring carbonation of beers.”
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, page 76.

I’ve mostly been around quite small Bavarian breweries. But every single one still had open fermenters. Even ones with a brand new brewhouse. Which tells me something: that there’s no artificial carbonating going on. Carbonation is achieved by bunging the lagering vessel and allow CO2 to build up naturally through the action of the yeast. As the temperature drops, more CO2 can be dissolved by the beer.

There are some truly weird bits in the Reinheitsgebot. Only allowing artificial carbonation with the CO2 produced during a beer’s own fermentation is one of the weirdest. It sounds like a fudge to me. That brewers wanted to carbonate artificially and this was a way to achieve that without using any extra ingredients.

Here’s a description of that carbonation process:

“Table XII compares various procedures for fermentation and maturation. In the classical method of primary fermentation and lagering, the residual extract of the beer after primary fermentation is about 3-5% (w/w). During lagering about 1-3% of this remaining extract is fermented, so that the finished beer contains about 2-0-2-2% of extract. The carbon dioxide generated during the lagering stage serves to purge the beer, improve the separation of precipitated proteins and tannins and to increase the carbon dioxide content of the final beer from about 0-25% w/w to 0-50% w/w.”
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, page 76.

Here’s an overview of the four main systems around at the time:

TABLE XII. Comparison of Fermentation and Maturation Systems.
Method	Primary fermentation	Transfer	Lagering
Classical	7 days at 9°C	Beer with 3-5% residual extract cooled to 4°C	35-50 days with temperature reducing from 3° to 0°C
Using Kräusen	7 days at 9º-10°C	Beer with 2% residual extract cooled to 4°C. 10-12% Krausen with 8% residual extract added	14-28 days with temperature reducing from 4° to 0°C
Under pressure at high temperature (Champagne Wheat Beer)	3 days at 16°C or 4 days at 14°C under pressure	Beer with 2% residual extract 2.0 bar pressure cooled to 0°C	7-14 days stabilization at 0°C
Modern development	7 days at 12-14°C with CO2 collection	Attenuated beer carbonated and cooled to 0°C	14-21 days stabilisation at 0°C and final carbonation

This is a method which had been around since the 19th century – adding fermenting wort, or Kräusen, to the maturing beer. It was popular in the USA, and not just amongst bottom-fermenting brewers. Amsdell of Albany kräusened their top-fermenting beers around 1900.

“The Kräusen method is used especially in those breweries where fermentation takes place in cylindro-conical vessels and maturation in classical horizontal lagering tanks. Since it is difficult to estimate the yeast concentration of green beer fermented in a cylindro-conical vessel it has been found advantageous to leave the beer in the vessel until no fermentable extract is left and the dispersed yeast cells are at a minimum. The green beer is then drawn off and Kräusen, which contains a fermentable extract of about 8-9% w/w and about 40 million yeast cells per ml, is added equivalent to 10-12% of the beer volume. This procedure is simpler to control than the classical method of leaving a certain amount of extract and also has the advantage that beers produced in this way may be filtered and bottled after only 21 days. The only problem with this method is that Kräusen with 8 % extract is not available every day and the beer has to remain in the vessels for different times until transfer. As a result, the fermenting cellar has to have a greater capacity than that calculated for the classical method.”
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, page 76.

Now isn’t that interesting? Kräusening was used because they needed to ferment the beer right the way down in the conicals. The British equivalent of this was to prime beers with a high-gravity sugar solution at racking time. Though Guinness did use high-gravity fermenting wort.

Champagne wheat beer is Kristallweizen. Not something I’ve ever cared for, myself. It always seems thin and rather dull, with the spiciness from the yeast rather subdued.

“We use the pressure fermentation method in Weihenstephan to produce the so-called 'champagne' wheat beer and it is obvious that our classical method using top fermentation can also be used with bottom fermentation. Green beer with a residual extract of about 5 % is pumped into closed fermentors, until a pressure of 2 bar is reached and the fermented beer contains 0.8 % w/w of CO2. This beer is cooled to 0°C and is then transferred to a 'stabilization tank' at a temperature of 0°C. After remaining in this tank for 7-14 days the beer is filtered and bottled. The advantage of this procedure is that the carbon dioxide originating during the fermentation from 5% residual extract to 2% residual extract is saved to carbonate and purge the beer. The disadvantage of the procedure is the necessity to have pressure tanks which can sustain a pressure of 2 bar but the costs of these pressure tanks are naturally not as high as the costs of installing carbon dioxide collection equipment. No modern brewery, however, will demand pressure fermentation but will collect all the carbon dioxide evolved during primary fermentation not only for carbonation but also for pressurizing intermediate tanks or filling evacuated bottles on the filling machine.”
Journal of the Institute of Brewing, Volume 83, Issue 1, March-April 1977, page 76.

So in this method they conducted the final stages of the fermentation in closed pressurised fermenters, which again allowed the beer to carbonate naturally from the CO2 being produced. No need to collect the CO2 and then add it back in the form of artificial carbonation.

More fermentation next time.

German brewing in 1966 – fermentation (part two)

We’re fair rattling through this article. Just a few more months and we should be done.

Fermentation is still the topic, though we’re moving from the traditional to the innovative. Or is that from good to bad? Obviously all that messing around in lager cellars was time-consuming and expensive. Reason enough for some to looking for a quicker and cheaper method.

“Newer methods of fermentation.—The so-called pressure fermentation had its origin in the production of champagne wheat beer with bottom or top fermentation, where it has been used for 35 years with the best of results. Before the pressure fermentation starts the wort must be cleared of trub. Then follows, with a bottom yeast, a short fermentation (24 hr.) at approximately 15° C, before the wort is pumped to a pressure tank at 17-18° C. This tank should only be filled to two-thirds of its capacity. The fermentation carries on for approximately 4 days to an attenuation degree of 63-67% with all valves open; subsequently this temperature is maintained, the valves are closed and a pressure of 2 atm. is reached. When the beer has been fermented almost to the final attenuation the tanks are cooled, either by jacket coolers or by internal coolers to 12° C, in order to cause the yeast to settle; this takes 1-2 days.

After a settling period, the beer is pumped to a further tank, as a result of which most of the yeast is removed; it is then cooled in several stages to below freezing point. At the same time, the pressure is dropped at intervals to the pressure corresponding with the required CO2 content. This period lasts for 10 to 14 days. The escaping CO2 produces a certain maturation and induces increases in colloid particles as well as in protein deposit.”
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, page 21.

Surely bottom-fermenting a wheat beer was a no-no under the Reinheitsgebot. By “champagne wheat beer” I’m pretty sure they mean Kristalweizen, or filtered wheat beer. I seems a weird mixture of open and closed fermentation. I’m quite confused by this knowing that today Weissbier is commonly open fermented, even at large producers like Schneider.

The cooling and pressurising process sounds very much like classic lagering, albeit considerably shorter at a maximum of two weeks.

35 years puts the origin of this method back in the early 1930’s. Which I find surprisingly early. The implication is that the technique was developed for Kristalweizen then applied to other types.

It did have some disadvantages:

“Beers produced with this method have a good head and if intensive cooling has been combined with good fermentation they also have good chill stability. Severe variations in output can result in over-aged beer or in insufficient brightness, which makes filter work more difficult.

Poor flavour can result if too much yeast is put into the maturing tank or if the required pressure is not reached or the maturing time is too short or much too long. The yeast should also be examined with regard to its ability to produce by-products of fermentation such as higher alcohols, volatile acids and esters. Our results show that the various yeasts differ clearly in this respect.

A yeast used during warm fermentation can only be used for a limited period; thereafter a fresh yeast from the conventional cold brewery must be obtained."
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, page 21.

OK, it had a nice head but tasted shit. Or at least did if conditions weren’t optimal. Clearly then yeast wasn’t too happy with this treatment as it couldn’t operate for long under these conditions.

But there was a way around these problems: blending.

“As a result of experience to date, it appears to be essential to blend beers fermented according to the conventional system with beers from the quick maturing system. By this means the output of "cold" fermented beer can be kept constant and the output of other beers can be varied. At the same time, this blending system prevents excessive ageing of beers when output stoppages occur. If pressure tanks are not available then a CO2 rinsing or washing system can have the same effect. In Germany, CO2 from the actual beer fermentation is the only type that can be used.
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, page 21.

That sounds a right pain in the arse. Because beer from a pressure fermentation couldn’t be left long in the brewery you also need to have beer that could. That is, beer produced the old-fashioned way. And you needed to have two sets of fermentation equipment to produce the two types of beer. Sounds expensive in terms of plant.

Only allowing CO2 produced during a fermentation to be used for artificial carbonation is one of the quirks of the Reinheitsgebot.

“A second method is more complicated. It depends, however, on the existing processes. By increasing the temperature in the fermentation cellar, final attenuation is reached and the yeast is removed by means of a green-beer centrifuge. This yeast-free beer can now be cooled by means of a heat exchanger unit to 4° C. without endangering the yeast. Subsequently it can be pitched with non-flocculating yeast. As the warm fermenter beer contains only small amounts of CO2, the non-flocculating yeast must provide CO2 saturation in 10-14 days, whilst at the same time the beer is cooled to less than 0° C. The combination of the easily fermentable "Krausen" extract with the intensively fermenting yeast completes this process. The resulting beer is well matured and, according to existing observations, good protein stability is obtained.”
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, page 21.

Let’s get this straight. The beer is fully attenuated during a warm primary fermentation and the yeast removed. It’s then cooled and repitched to carbonate the beer. It sounds like this was all done with the classic fermentation and lagering equipment.

“Beers brewed according to this method have a satisfactory and stable flavour. It is, nevertheless, necessary to reduce the high pressure in the green-beer centrifuge as otherwise severe aeration of the beer occurs, resulting in a detrimental flavour due to diacetyl and other factors. Kieninger has suggested a modified quick-maturing method in which green beer is centrifuged with a low back pressure and cooled to 0° C. before or after centrifuging. By means of corresponding pressure regulation it is possible to introduce CO2 in excess into the centrifuge and the subsequent rest period is utilized for releasing the C02 at intervals, so that the action of the C02 on the large surface area produces a maturing of the beer. This method is still experimental but experiments to date have been giving encouraging results.

These methods have made it possible to produce a satisfactory beer in 10-20 days from the date of brewing by modifications of the existing fermenting and maturing methods.”
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, pages 21 - 22.

The difference between this and the preceding method appears to be artificial carbonation rather than a secondary fermentation with new yeast.

The time taken to produce beer was about halved using this method. Remember the classic method entailed a least a week in primary and four weeks lagering – 35 days in total.

Filtration next time. That sounds like fun.

German brewing in 1966 – fermentation (part one)

Not too far to go now. Before you know it we’ll be done and I’ll have to think up another interminable series.

Were now at one of the most vital phases of beer production, fermentation. Where the yeast works its magic and turns dull sugars into exciting alcohol. My favourite constituent of beer.

“The Main and Secondary Fermentation
During the last ten years exact control of fermentation has been made possible by the use of suitable flocculating and non-flocculating yeasts. The characteristics of a large number of yeasts were known and it was possible to obtain small quantities of yeast in optimum conditions from the appropriate institutes. However, the quantities required were occasionally so large that even smaller breweries could introduce their own yeast culture plants. The main fermentation was carried out at 5-9° C. for 7-12 days. Yeast was pitched at a rate of 0.3 and 1.0 litres to the hl. and the usual intention was to reach 90% of the final attenuation in the fermentation cellar.”
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, page 20.

Contrast that with a typical top fermentation:

“The wort is pitched as soon as possible using pressed yeast at a rate of 0.15 to 0.30 kg/hl (0.5 to 1.0 lb/imp. brl). Traditional practice is to pitch at 15± 16º C (+-60º F) and allow the temperature to free rise to 20-24º C (68 to 75º F, Fig. 14.1) as fermentation proceeds. This is rapid and normally finishes in around 48 hours.”
"Brewing: science and practice", by Dennis E. Briggs, Chris A. Boulton, Peter A. Brookes and Roger Stevens, 2004, page 528.

Having spent many a happy hour looking at fermentation temperatures in brewing logs, I can say that Briggs is bang on the money there. Though four or five days is a more typical duration for primary fermentation.

It’s a bit difficult to compare pitching rates as one is given as a weight and the other as a volume. However, it’s obvious that 1 litre of yeast is going to weigh considerably more than 300 gm. The much higher pitching rate for bottom-fermentation is presumably why it was worth the while of even small breweries to have their own yeast propagation system.

Now on to secondary fermentation, or lagering:

“The secondary fermentation at a temperature of +4° to 0 or -1° C. continued for 8-12 weeks. The desired final degree of attenuation was not always reached, so a certain percentage of non-flocculating yeast was used as secondary fermentation yeast or alternatively one, added 6-10% of a two-day old primary fermentation beer. When these methods were properly applied, beers of excellent quality could be obtained. In classic fermentation systems one requires large fermentation rooms with a capacity of one-twenty-third of the yearly output. The storage cellars require a capacity of one quarter of the yearly output in order to allow for the summer peak. These methods are today still used in the breweries of Dortmund and Munich as well as in many other large and small breweries, where every increase in capacity of 1000 brl. per year results in a corresponding increase in the fermentation and storage cellar. Other breweries are looking for a way to avoid new building and as a result of replacement of wooden storage casks with modern tanks a considerable increase in the brewery's capacity can be achieved without difficulty, as a storage period of 8-12 weeks still enables certain reserves to be made available. In addition, fermentation and storage might be saved by cold filtration of the wort, but even this method gives a minimum of 1 week's main fermentation and 4 weeks' secondary fermentation.”
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, page 20.

The first part of the paragraph is a description of the classic method of brewing Lager. A cool primary fermentation followed by a long, slow secondary fermentation at around freezing.

Adding young, fermenting beer is usually called “kräusening”. The only real record I have of this practice is from Amsdell, an Ale brewery in Albany New York, from around 1900. They were adding a far larger volume of Kräusen – about 25%.

I wonder where that figure of one-twenty-third comes from? I presume it’s based on a batch taking approximately two week in primary fermentation. The one quarter for the lager cellar is easier to work out. If beer was going to be lagered for three months, you’d need about three months’ worth of beer in the lagering cellar.

Reducing the fermentation time is an obvious way of saving money. Nowadays I’m sure the big industrial brewers rush their Lagers through in less than five weeks. I’m not sure that they even lager at all really.

Here’s what happens when the fermentation is rushed too much:

“Frequently attempts were made to obtain a quick fermentation by increasing the pitching quantity and the fermentation temperature (9-12° C.); usually the secondary fermentation intensity was no longer satisfactory as the yeast adapted itself to the higher temperature and received quite a shock as a result of the quick cooling in the storage cellars. The unsatisfactory second fermentation produced beers with insufficient maturity; by-products of fermentation were evident in greater quantities and reduction of diacetyl and acetoin was unsatisfactory. The beers had an unfinished yeasty flavour, a rough bitterness and insufficient CO2 and head stability; continuously changing character and insufficient secondary fermentation affected the normal increase in colloid particles and protein deposits which is necessary for the stability of the finished beer. In these cases an improvement in quality had to be obtained by means of increased use of filter aids and absorption-stabilizing media, in order to obtain beers with the required characteristics. In this connection, it was also useful to replace a large part of the flocculating yeast by non-flocculating yeast which, however, caused difficulties with beer filtration.”
Journal of the Institute of Brewing, Volume 72, Issue 1, January-February 1966, pages 20 - 21.

9-12° C isn’t far off a top-fermenting temperature. No surprise that the yeast didn’t like being chilled down to near-freezing after getting used to the warmth. But I wonder how many of these faults are present in today’s mass-market Lagers? Maybe not the diacetyl, but I’ve had Lagers with rough bitterness. When you could spot the bitterness, that is.

Next time we’ll be looking at newer methods of fermentation.

German brewing in 1960 - fermentation and lagering

Isn't this fun, our stroll through the kitchen garden of the past? Just keep an eye out for wasps.

We're going to kick off with fermentation, the heart of the brewing process.

"Fermentation.— Standard practice in 9 of the 10 breweries visited was to arrest fermentation at a suitable attenuation for racking to the lager cellar. Temperatures were in the range 40-48° F. and much variation in yeast behaviour was apparent, comparable attenuations taking from 5 to 14 days. All the larger breweries had pure-culture yeast propagators in operation and yeast washing was general. Liquor at 34° F. was used and storage was generally under this liquor as a thick paste. Pitching rate was measured volumetrically: from 0.3 to 0.5 litres of the pasty yeast was pitched per hectolitre of wort, i.e. approximately 1.5 lb. per brl. for 1045° wort. Fermenting vessels were predominantly of ebon or aluminium, with newer installations in stainless steel but rarely enclosed. Mixing of worts often took place in large starting tanks and attemperation was by cooled drinking water at 34° F. It was common practice to skim off the resinous scum with a perforated scoop just before racking."
Journal of the Institute of Brewing, Volume 66, 1960, page 500.

The obvious question is what did the tenth brewery do? And how did the nine stop fermentation? By cold crashing?

Let's so how that compares with British practice. This is the fermentation record of Barclay Perkins Export from 6th November 1962:

You can see that it was pitched at 45º F and most of the fermentation was round 48º F, putting at the top end of the German range. While at 10 days, the primary fermentation was on the long side. I was going to compare the pitching rate, but unfortunately I can't understand the yeast details in Barclay Perkins Lager logs. Can you tell me what 61/3 + 13/3 means? I thought not.

Instead I've looked at Whitbread PA from 26th October 1959. A beer of 1039.5 which received 0.8 lbs of yeast per barrel. About half the German Lager rate. It makes sense that you'd need to pitch a lot more yeast in a Lager.

Barclay Perkins both repitched yeast from earlier brews and used pure propagated yeast in their Lagers. They never used pure yeast in their top-fermenting beers, only repitched harvested yeast.

This doesn't quite tally with what I've seen in the fermentation rooms of small Bavarian breweries. True enough, the fermenters are open. But the wort isn't cooled with attemperators inside the fermenter. The whole fermentation room is kept refrigerated. Fermenting vessels mostly seem to be made out of stainless steel, though it's hard to tell when they're filled with wort.

Now lagering:

"Lagering.— In German cellars it was essential to allow tank pressures to rise to between 6 and 9 lb. per sq. in., as no further artificial carbonation was allowed. Bentonite was commonly added to the lager tank, and bunging tended to be individual, with not more than 3 tanks in a column. Cellars were often maintained at a temperature just below freezing, particularly with export beers, to allow maximum precipitation. Storage periods varied from 2-6 months, with one extreme case of 9 months in a brewery with extensive storage space. New tanks were of aluminium, but pitch- and glass-lined iron tanks were common and many old wooden casks of up to 50-brl. capacity persisted in Bavaria."
Journal of the Institute of Brewing, Volume 66, 1960, page 500.

The original method of carbonating Lager was to seal - "bung" - lagering vessels after a certain time to allow pressure to build up inside them and the beer to naturally carbonate. This was the process recommended for brewing Harp Lager in the early 1960's. I'm sure they quickly dropped the practice and switched to artificial carbonation. German brewers had no option, being limited in their actions by the Reinheitsgebot.

The classic lagering period is 1 week per degree Plato of the beer. So a 12º Pilsner needs 3 months lagering, an 18º Dubbelbock 4.5 months. 6 months seems long for anything other than a Bock. From my inquiries at various Franconian breweries, modern lagering times are between 2 and 4 months. At least amongst small, old-fashioned breweries. I'm sure they're much shorter at the big boys. If they bother lagering at all.

Not sure how many still use wooden lagering vessels, even in Bavaria. The only ones I've ever seen in use were at Brauerei Schmitt in Singen, a museum brewery. Even there it looked like they were being replaced by metal tanks. And the only more old-fashioned breweries I've ever seen were communal Zoigl brewhouses.

Next time it will be packaging. How exciting.

Danish brewing in 1960 - lagering and packaging

It's a sad day. My little series on Danish brewing is drawing to a close. We'll be looking at the final phases of the brewing process.

Starting with one of my favourite processes, lagering. I've seen a fair bit of discussion on homebrewing fora about how long you need to lager and even whether there's any point in bulk lagering at all. I won't claim to understand the science, but from my experience drinking beer, a proper long lagering definitely helps. All the Franconian beers I love get at least two months.

"Lagering.—The green beer was racked to the lager cellar by pumping. The yeast had usually compacted firmly on the floor of the fermenting vessel and it was not appreciably disturbed during racking, so that a retaining collar was rarely necessary. Much mixing of gyles took place in order to obtain a consistent product and also, where the method was in use, to mix yeast types. At this point in the process precipitating agents such as tannic acid were sometimes added.

Cellars were maintained at about 32° F. and the beer was allowed to reach this temperature naturally, standing in tanks which were bunged about a day after filling, either column-wise or singly. Many cellars were vast underground refrigerated passages, but new installations above ground enclosed the tanks in cold rooms, leaving the ends accessible from a working passage at room temperature. Enamelled iron, aluminium and stainless steel were used for lager tank construction, with aluminium now predominant. Pressures were allowed to rise to about 4 lb. per sq. in., which is lower than in Germany where subsequent carbonation is not allowed, and the average storage time was up to 3 months for Pilsner types and 6 months for very strong beers."
Journal of the Institute of Brewing, Volume 66, 1960, pages 497 - 498.

Blending gyles is typical of big industrial breweries who want to maintain absolute consistency of flavour. For me part of the charm of some beers is that there are slight variations from batch to batch. Makes life more interesting.

The lagering process sounds pretty traditional: gradual cooling to about freezing point and bunging the lagering vessels to allow the beer to carbonate. Though obviously they didn't solely rely on natural carbonation as the Germans did. Funnily enough I know from documents in the Barclay Perkins archives that Harp Lager was bunged and naturally-carbonated in the early 1960's

Now filtration, a vital part of Lager production.

"Filtration and bottling.— In 14 of the 16 breweries visited in Denmark and Germany, the final polishing filtration was given by a pure cotton cellulose pulp filter of the Enzinger type. Pulp polishing was considered essential for stability of the finished beer, in spite of the disadvantage of regenerating and sterilizing the pulp and the possible loss of beer quality. Four of the Danish breweries used a battery of centrifuges for rough filtration, with additional cooling equipment between the centrifuges and the pulp filter; they were not so efficient as kieselguhr rough filters and they thrust more load on to the polisher. For example, a 50-plate pulp filter used after a centrifugal pre-filter passed about 300 brl. before choking whereas 400 brl. were passed after prefiltration by kieselguhr. The sludge from the lager tanks was usually filtered through a cloth filterpress, and the beer recovered was led through the main filtration plant and metered into fresh bright beer."
Journal of the Institute of Brewing, Volume 66, 1960, page 498.

I've included that for information purposes only I can't claim to understand hardly any of it. My knowledge of filtration methods is close to zero. Not anything I ever bothered with when home brewing. Very efficient of them to recover the beer in the yeast sludge. Better than the disgusting practice of some British breweries of reusing returned beer.

Now they're fizzing the beer up.

"Carbonation took place just before the pulp filtration, and bright-beer tanks were usually glass lined. Two large breweries had a rigorous check on dissolved air before bottling, and any excess over 2 ml. per litre was scrubbed out by bubbling carbon dioxide through the tank. The extent of carbonation was standardized and chill-proofing agents were sometimes added. Bottling lines were always well laid out, with hot water spray pasteurization in bottle commonly applied; the usual practice of a 20-min. hold at 143° F. for a 0.33-litre bottle seemed rather drastic."
Journal of the Institute of Brewing, Volume 66, 1960, page 498.

I can't really say much about this either. Other than that large breweries were clearly concerned about oxidation and that pasteurisation seems to have been standard. Though that was also true of British bottled beer at the time, with just a handful of exceptions.

Finally, draught and canned beer.

"Keg beer constituted a proportion of the home trade of some breweries, and here pasteurization by complete immersion was favoured for thorough heat transfer and so that leaking kegs could be detected. Export beer in bulk was flash pasteurized. Canning was rather the province of the major concerns, but it was obviously on the increase and at least one firm was preparing to raise its output of canned beer extensively. Standards of stability for beer in bottle were high. Vibration and forcing tests were regularly carried out with, e.g., one type of beer being expected to withstand a temperature of 140° F. for 3 months without throwing an appreciable haze."
Journal of the Institute of Brewing, Volume 66, 1960, page 498.

I can remember being shocked during my first visit to Copenhagen back in the 1980's at the almost total absence of draught beer. Even in largish city-centre pubs, draught beer was rare, except in British or Irish pubs. It was the only real beer-drinking country where bottles so completely dominated the pub trade. That's one of the many aspects of the Danish brewing scene which have completely changed. Now draught beer is everywhere.

It sounds as if not all breweries really bothered with draught in 1960, but some did. But presumably between 1960 and 1980 even those gave up on it.

Next we'll be looking at German brewing in 1960.

The Pfaudler vacuum system

Not sure why I never posted this before. I'd used the rest of the article discussing American brewing.

Maybe because this section is about Lager, though it does have a British connection. In fact it's connected to a couple of my obsessions.

First, confirmation that American brewers didn't decoct their Lagers:

"Although the manufacture of lager beer must necessarily be of less interest to the English brewer than that of the high fermentation ale, I may perhaps be permitted to call your attention to a few modifications -which the Americans, with their accustomed originality, have introduced into the time-honoured continental methods. In the first place, one is struck by the almost complete abandonment of the decoction mash. Nearly all the lager in America is brewed by the infusion process, either as we know it, or by a system of gradual elevation of temperature in the mash-tun. The boiling of the "thick mash" is practically unknown.

The method of fermentation of lager, as generally adopted, differs but very little from that of continental breweries. The primary fermentation is carried on at from 40° to 41° F., and lasts from 14 to 20 days. The beer is then passed on to tall vats, which are known as the ruh casks, and here it remains from one to four months. It is then run into the "chips-casks," where it is at once kräusened with fermenting wort, to the extent of from 15 to 20 per cent., and bunged down tight. Finings are sometimes added at this stage, and when the beer is nearly brilliant it is passed through a Stockheim or Enzinger filter, and racked into the trade casks. The primary and complementary fermentations together last from 2 to 5 months, so that the space and plant required for a brewery doing a good trade are very considerable, and of course the working capital is correspondingly large."
Journal of the Federated Institutes of Brewing, Volume 3, Issue 6, November-December 1897, page 475.

That's very much the classic method of fermenting Lager: a slow, cool primary fermentation, a long lagering,  kräusening and bunging to carbonate the beer. Though I'm not sure Continental breweries would have used finings. Two  to five months is a pretty decent lagering time. Interesting that the use the German word "ruh", meaning rest. And, like Budweiser, they were adding wood chips to the lagering vessels.

Obviously that was an expensive and time-consuming process. No surprise that there were attempts to shorten and simplify it.

"An attempt has been made within the last few years to materially lessen the time required for the complete fermentation of lager, and thus to reduce its cost of production.

The process is known as the "F. F." or Pfaudler vacuum system, and as it is one which is attracting a good deal of attention in America and elsewhere at the present time, it will doubtless be of some interest to you to hear something about it.
. . . . .

Briefly stated, the principle of the process depends on three conditions:—(1) The temperature of fermentation is much higher than that-usually employed in lager beer brewing; (2) there is a certain amount of aeration during the process which admits of strict regulation; and (3) the fermentation is carried on under low pressure conditions which admit of the carbonic acid being removed as fast as it is produced. Under these three combined influences the fermentation runs through a very rapid course, and the beer is ready for the chips-casks in from 10 to 11 days. If the process of krausening in the chips-casks is adopted the beer is ready for racking in about three weeks from the time of brewing, a time which may be further reduced to 11 or 12 days if the chips-cask stage is avoided by carbonating the beers."
Journal of the Federated Institutes of Brewing, Volume 3, Issue 6, November-December 1897, pages 475 - 476.

Remember where we've heard of the Pfaudler vacuum system before? It's the system that Allsopp installed in Burton in 1899 when they decided they wanted to brew Lager. And which was taken by Calder up to Alloa.

It's nice to learn exactly what the Pfaudler vacuum system was.

"The following is a brief description of the vacuum process of fermentation :—

The worts are first run into "starting tubs" at about 50—51° F., and the yeast is added at the rate of about 1 lb. per barrel. After 24 hours it is transferred to the vacuum vessels, which are large cylinders, built up of steel sections, rivetted together and coated inside with a special enamel which is burnt on to the cylinders. The bottoms of these cylinders are conical, and they resemble somewhat in general appearance very large pure-yeast cultivators.

The top of the cylinder is closed, and arrangements are made for pumping out the carbonic acid and for reducing the pressure in the apparatus to any desired extent by means of an air-pump. The carbon dioxide can, if desired, be collected and liquefied by pressure in ordinary gas cylinders, and then used directly for carbonating the ale when it is finished. There is an air inlet in the conical bottom, connected inside with a perforated loop of pipe, through which air (previously well filtered through cotton wool) can be passed into the fermenting wort. This air passes through a "sight feeder" on its way to the vacuum vessel, so that the amount which passes can be easily regulated.

During this part of the process the temperature is not allowed to exceed about 49° F., by means of an attemperator in the vacuum vessel, and the fermentation is complete in from five to seven days. The Phoenix Brewery at Pittsburg has 26 of these vacuum vessels, each holding 110 American barrels, and they are sufficient for turning out 100,000 barrels per annum."

After the primary fermentation is over, the beer is of course in an extremely flat state, and is either passed on to chips-casks and kräusened, or is at once filtered and carbonated before being put into the trade casks.
Journal of the Federated Institutes of Brewing, Volume 3, Issue 6, November-December 1897, pages 476 - 477.

So the primary fermentation was around 10º F warmer and one or two weeks quicker than the classic Lager method. I can see how that would save a brewery dosh. It sounds like minimal lagering was taking place. Which would have been an even bigger economy.

The vessels themselves, apart from the vacuum bit, sound very much like conical fermenters. Though much smaller than modern conicals usually are.

The system was quicker, but did the finished beer taste as good as that produced by the classic method?

"The Pfaudler vacuum system is certainly able to produce a lager beer much more rapidly than the old system, but what proportion of capital outlay in required to construct a brewery of given out-turn on the old and the new system respectively I am not at present in a position to say. Assuming, however, that the balance, as regards initial cost, is in favour of the new system, and that the much more rapid turnover is taken into account, the final verdict must after all turn on the relative quality of the beer produced by the two processes. That a perfectly sound and saleable article can be produced by the vacuum system is an undeniable fact, but whether the longer storage and maturation of the beer brewed on the old system does not produce certain high class qualities which are lacking in the more quickly made and loss matured vacuum beers can only be determined by a lengthy trial and by the competition of trade, which can alone decide which of the two is the fitter for survival. At present I hold my judgment on this question in suspense."
Journal of the Federated Institutes of Brewing, Volume 3, Issue 6, November-December 1897, page 478.

I take that as a definite maybe. My personal experience tells me that a couple of months lagering definitely improves a beer. If it didn't why would anyone still bother?