Lagering in a Keg

[cooper]

Just wondering if anyone does their lagering in a keg? Two or three weeks primary (depending on what the hydrometer says) at 52F and then into the keg for at least a month at near freezing (again depending on the starting gravity of the beer, what I use is 1 week per degree Plato from the day its brewed is how long its lagered before I start tasting).

What I'd like to know is does anyone put any pressure on if they lager in the keg? I've read some stuff where people will put 10lbs of pressure on the keg and let it sit for the lagering time.. What do you guys think?

 

[wildwest450]

I only lager in kegs. You can purge with c02(30psi), and let sit. You will find that at those low temps the headspace will clear out in a few days as the c02 absorbs into the beer, I just carbonate as i'm lagering.


_

 

[cooper]

Heck that makes things even easier.

 

[Hammy71]

Like wildwest said. I only lager in kegs. If I have an extra CO2 tank thats not being used, I'll carbonate at the same time.

 

[jeffd10]

i only lager in kegs. You can purge with c02(30psi), and let sit. You will find that at those low temps the headspace will clear out in a few days as the c02 absorbs into the beer, i just carbonate as i'm lagering.


_

+1

 

[BrewThruYou]

So if you lager in a keg, you don't bother jumping it to another keg for carbing to leave sediment behind? Or maybe I should just picnic tap a little bit out? I used to lager in glass, but now lager in kegs.

 

[sonex]

if you cold crash before you transfer to keg there will be little sediment on the bottom of your keg. so there is no reason to transfer after lagering.

 

[ajdelange]

But you don't want to do that. You want quite a bit of yeast in the lagering vessel. Without them proper lagering cannot take place.

 

[sonex]

But you don't want to do that. You want quite a bit of yeast in the lagering vessel. Without them proper lagering cannot take place.

even with cold crashing there is going to be some yeast being transferred so this is not a concern.

 

[Malticulous]

I don't want yeast when lagering. When I lager I'm done with them. That's the old way. They'd leave it at 40F for a few weeks to mature and carbonate. The diacetyl rest does the maturation, so will a long primary.

 

[sonex]

I don't want yeast when lagering. When I lager I'm done with them. That's the old way. They'd leave it at 40F for a few weeks to mature. The diacetyl rest does that, so will a long primary.

very true the yeast at close to freezing would be dormant anyway. the lagering stage is just to improve flavor kinda like why wine and spirits are aged.

 

[ajdelange]

Then don't have them. You won't get as good a beer but you must do as you choose.
In the first place, a diacetyl rest without yeast present will not result in reduced (lowered concentration sense) diacetyl because the reduction (transfer of electrons sense) takes place within the yeast cell. In the second place, full maturation just takes time. There is no way that a beer which has been rush lagered will have the mellowness and smoothness of one that has lagered 3 months or more. A further advantage of lagering for long periods on the yeast is that the beer stays fresh for a year or more and continues to improve for most of that time. Again it is the ability of the yeast to keep the beer in the reduced state that enables this. Eventually, of course, the yeast do give up the ghost and there is a decline in quality but as noted that's usually more than a year out.

A couple of other notes: You don't cold crash a lager. You bring the temperature down about 1 °F per day. And you go to temperatures well below 40 °F if you can. Close to freezing is ideal.

Check out Noonan's book.

 

[Spartan1979]

Then don't have them. You won't get as good a beer but you must do as you choose.
In the first place, a diacetyl rest without yeast present will not result in reduced (lowered concentration sense) diacetyl because the reduction (transfer of electrons sense) takes place within the yeast cell. In the second place, full maturation just takes time. There is no way that a beer which has been rush lagered will have the mellowness and smoothness of one that has lagered 3 months or more. A further advantage of lagering for long periods on the yeast is that the beer stays fresh for a year or more and continues to improve for most of that time. Again it is the ability of the yeast to keep the beer in the reduced state that enables this. Eventually, of course, the yeast do give up the ghost and there is a decline in quality but as noted that's usually more than a year out.

A couple of other notes: You don't cold crash a lager. You bring the temperature down about 1 °F per day. And you go to temperatures well below 40 °F if you can. Close to freezing is ideal.

Check out Noonan's book.

For a lager fermenting at 50° F, what temperature do you recommend for a diacetyl rest?

 

[Malticulous]

Noonan is kind of old. I have read it and I do like it.

This is from my newest book.

12P, pitched 10x10^6/ml, temp ramped from 48F to 60F. Crashed at one week. (Conjecture and assumptions.)

I can find better quotes if I look, I just really like the graph.

 

[sonex]

I never said anything about a diacetyl rest if you believe you need one then do so and then bring down to lagering temps for a few days and then transfer to your keg for lagering. But to be honest if you pitch with enough yeast at or below fermentation temps and ferment at 48-50 a diacetyl rest more than likely would not be necessary.

 

[ajdelange]

For a lager fermenting at 50° F, what temperature do you recommend for a diacetyl rest?

In my experience if you ferment at 48 °F to within 1 °P or so of expected terminal gravity and then from that point slowly lower to near freezing and hold there for a couple of weeks you won't need a diacetyl rest. No one ever comments on diacetyl in beer made this way to the point I've quit measuring it because it is a big PITA to do so and the result was always that it was right at threshold. Plus, and this is important in looking at plots like the one posted by Malticulous, the common hydroxylamine/glyoxime test picks up acetolacte (the precursor) as well as diacetyl. This is really good though because the goal is have diacetly at threshold or below and to keep acetolactate (which will turn into diacetyl once the yeast are removed) out of the package.

Diiacetyl is not produced by the yeast but acetolactate is. Acetolactate is non-enzymatically oxidized to diacetyl external to the cell after fermentation has peaked. Uptake (two reductions to respectively acetoin and 2,3, butane diol) do take place within the cell. All methods of diactyl reduction thus require active yeast. In modern mega brewing yeast activity is insured by raising the temperature and the amount of diacetyl/acetolactate goes down but note that there is a residual. There is no scale on the graph but we must presume that the reduction is to threshold or lower as once the yeast is removed diacetyl reduction is over but diacetyl production can continue.

The graph represents typical modern megabrewing practice. Beer which approaches, at least to Joe Sixpack, beer made by the traditional method, is produced in a week!. This is a remarkable technological achievement but there is a downside. I liken the modern brewing industry to the modern motion picture industry. The technology is amazing but the overall result is insipid.

By contrast in the traditional method the nearly finished beer is gently cooled to avoid shocking the yeast and transferred to the lagering vessel with plenty still in suspension. Over the next few months the yeast cells, still active at near freezing temperature, reduce diacetyl, acetaldehyde and jungbuket and keep the beer in a reduced state (low ORP) with the final result being a better product. Flavors are melded, mellowed, smoothed and rounded and, though I can't begin to explain it, the CO2 melds as well. Properly lagered beer is never "fizzy".

In my own brewing I go straight to the keg after cold conditioning for about 3 weeks. The first keg goes on tap immediately and one of the most fascinating things about the process is frequent sampling of the beer thereafter. Often it is good at the outset (in fact we sometimes drink it from the Zwickle) but it is definitely "green". What's interesting is that it stays green and stays green ans stays green and then turns overnight. At this point (usually about 3 weeks in) it is pretty clear and definitely ready to drink. But the show isn't over yet. It will continue to improve for up to a year and, as I mentioned before, that is because it is sitting on the yeast. The improvement isn't always monotonic but it usually is and, as I noted in an earlier post, eventually comes to an end. If I've planned well that's about the time the last keg runs out.

If, at any time in all of this, you need to pull off some beer for a party, to put into a contest or whatever, you just do that. That beer is then off the yeast and needs to be consumed fairly quickly as the yeast are no longer there to stabilize it and, if you went to bottles, you introduced some air which the yeast aren't there to scavenge.

Perhaps I could summarize by saying that beer stored on living yeast is a living thing i.e. it has a life of its own. Following that life cycle is, for me, one of the most enjoyable and fascinating aspects of brewing. Clearly this post represents some personal preferences and these are, obviously, influenced by personal taste. I am not saying that the high temp/diacetyl rest program should not be used. I'm just saying it's not right for me. If you prefer beer made that way then by all means make it that way. The final word: if lager fermentation and lagering are carried out properly there is no need for a diacetyl rest.

 

[pjj2ba]

................Often it is good at the outset (in fact we sometimes drink it from the Zwickle) but it is definitely "green". What's interesting is that it stays green and stays green ans stays green and then turns overnight. At this point (usually about 3 weeks in) it is pretty clear and definitely ready to drink. But the show isn't over yet. It will continue to improve for up to a year and, as I mentioned before, that is because it is sitting on the yeast. The improvement isn't always monotonic but it usually is and, as I noted in an earlier post, eventually comes to an end. If I've planned well that's about the time the last keg runs out.

.................I am not saying that the high temp/diacetyl rest program should not be used. I'm just saying it's not right for me. If you prefer beer made that way then by all means make it that way. The final word: if lager fermentation and lagering are carried out properly there is no need for a diacetyl rest.

Both of these are what my experience has shown me as well. The change in flavor is quite dramatic. The most dramatic was 2 years ago I made a Czech pils (which ended up being the first time I thought I nailed the style). When I first put the keg on tap, as expected it was throwing a bit of yeast. I was amazed that it tasted like a good pale ale. The yeast cleared, but it was still very pale ale-like. Then is if by magic, it turned into a wonderful Czech Pils

I never do a diacetyl rest and have never had issues. I always chill a couple degrees below fermentation temps and then pitch.

 

[Malticulous]

I'm set in my ways, not only because it produces the quality I want in less time but because it dosen't cause problems in my pipeline. I simply don't have a different temp controlled fridge for every beer I have fermenting.

This time of year I primary lagers in a water bath in my brew shed. Temps stay 48-52F. After week or so when fermentation slows I'll move it in the house 60-70F. It tends to be 10-15 points above FG. I let it sit at room temp longer than I need to, normally 3-4 days. Then the primary is crashed for a few days maybe longer it depends. I have lagered in primary. From there I prefer to rack it to keg If I have an emplty. I'll fine it then(many commercial breweries will centrifuge or filter before lagering--not only to get the yeast out of the beer but to get all the beer from the yeast!), other times it goes into a carboy or I might bottle it. It's lagered 3-6 weeks. I've found some high gravity lagers are good in less time than some low gravity lagers. It's ready when it taste good.

It's simple, works with my brewery and I'm quite pleased with the results. I'm sure the more historical lagering practices work fine. It's just not for me.

But you don't want to do that. You want quite a bit of yeast in the lagering vessel. Without them proper lagering cannot take place.

 

[cooper]

It's interesting how much diversity we can have in our processes and still produce quality lagers.

 

[pjj2ba]

It's interesting how much diversity we can have in our processes and still produce quality lagers.

Exactly! As soon as someone starts saying you must do it this way, politely thank them for their opinion, and go and do it the way you want to (more than likely not the way they said)

 

[ajdelange]

But it often pays to try to understand why the guy recommends what he did. In most cases those that dig their heels in have no real basis: "I've always done it this way and I won BOS in 2004 at the Overshoe Open". But sometimes they do and it may be possible to glean something of value.

"Mind like parachute. Function best when open." (Old Charlie Chan movie)

 

[cooper]

But it often pays to try to understand why the guy recommends what he did. In most cases those that dig their heels in have no real basis: "I've always done it this way and I won BOS in 2004 at the Overshoe Open". But sometimes they do and it may be possible to glean something of value.

"Mind like parachute. Function best when open." (Old Charlie Chan movie)

I agree that it's always best to keep an open mind and at least be willing to consider what other people consider best practices. I've always been willing to give it a shot and see if it turns out to be something I adopt for my own practices.

 

[pjj2ba]

Quote:
Originally Posted by ajdelange
But it often pays to try to understand why the guy recommends what he did. In most cases those that dig their heels in have no real basis: "I've always done it this way and I won BOS in 2004 at the Overshoe Open". But sometimes they do and it may be possible to glean something of value.

"Mind like parachute. Function best when open." (Old Charlie Chan movie)

I agree that it's always best to keep an open mind and at least be willing to consider what other people consider best practices. I've always been willing to give it a shot and see if it turns out to be something I adopt for my own practices.

Agreed! If a person is willing to back it up with a valid reason then there might be something to learn. I have tried my share of crazy ideas, but I always felt there was a sound reason to try them (ie. lecithin works great at negating the affects of really oily ingredients - including straight oils!)

Plus I'm always cautious when making recommendations and always try to make it clear that it works on MY system, but your mileage may vary.

 

[Malticulous]

This is from Dan Gordon in Zymurgy Nov/Dec 2011.

The classic German lagering is two weeks at 39F and four weeks at 32F.

It makes much more sense than just "slowly lower the temp". There is more precise info in the recipes including the number of days to ferment. It lacks pitch rates but I'd have to bet on 1.25x10^6/ml per degree plato that Kai has quoted from Narziss or less. He said they propagate fresh for every batch.

It's good article and worth a read. He highly recommend lagering in a keg.

 

[ajdelange]

By contrast the classic lagering for Boh Pils is (or more probably was - don't see how they could compete today) 90 days at close to freezing. Don't recall whether they paused at an intermediate temperature.

The point about the rate of temperature change is that you don't want it to be abrupt. You don't want the yeast to flocculate and fall out. A degree per day is considered safe.

 

[Malticulous]

I'm sure Dan dosen't have that problem. 100000+ barrels probably can't be cooled too fast. The fact is he did not emphasize it.

He did say this in the Marzen recipe.

Ferment 7 days at 48F, lower to 43F for four days, then reduce temperature 2 degrees Fahrenheit a day until the temperature is at 32F. Lager six weeks.

None of the others mention it or lager as long.

 

[ajdelange]

Guess I'm not really sure what the point is here but if it that there are as many lagering programs as there are mashing programs that is true. In looking briefly through perhaps a dozen texts I came up with a dozen different answers reflecting the country (British/German/Belgian/US) in which the book was written and the time at which it was written (Classic like DeClerck or latest edition of Handbook of Brewing). Without trying to summarize them all a few example may be of interest. DeClerck (Belgian, 1950's) says lagering time for 12 ° beer is 2-1/2 to 3 months. Narziß (German, modern) says 4-8 weeks for 11 - 12° beers. For 12.5 - 14° he says 6 - 12 weeks; for festbiers 3-6 months and claims that the long lagering is responsible for the "especially pleasing floral aroma" of these beers (not really relevant to the discussion but interesting nevertheless). At the less academic level Noonan also recommends differing lagering times dependent on the gravity and type of beer.

As for temperature: there is some variability there too but all authors are consistent in saying that at least part of the lagering should be done near, or even a degree or so (C) below freezing.

I don't know who Dan is nor why he didn't mention that cooling needs to be gradual but if it isn't the yeast will drop out and be unavailable to fulfill their very important roles in lagering. All lager brewers know this. Now, of course, if you plan to get yeast into the lagering tank by kraeusening then you could crash the beer or even filter it the point here being that active yeast, from whatever source, must be present in the lagering beer


In modern brewing practice, of course, the long lagering times cited above are not used. J.L. Coors, in his chapter in the 1977 edition of The Practical Brewer, estimates that up to 40% of the capital expenditure in a brewery could be taken up by lagering vessels and that's with the modern process which "...produces a highly acceptable beer but it can be distinguished from beer made from worts of similar hstory and composition processed according to the traditional process." Again not really relevant but especially interesting in that he doesn't offer an opinion on the relative quality. Given his last name that isn't surprising. Actually, I guess that is relevant. No commercial operation, given that it can make "highly acceptable" beers with a 'lagering' period of a week or 2 is going to treble or quadruple its lagering time and in so doing multiply its necessary capital expenditure.


Now if the point was that I don't do what Dan does - I have no doubt on that score. Nor do I doubt that what he does works well for him. I don't do exactly what Noonan, or Narziß or Kunze or any of them describe. I do what is consistent with the science underlying what these authors recommend tailored to the practicalities of my equipment. I lager in kegs (where this thread started) and as such don't want to fiddle with Kraeusening (nor would I ever have a second batch of the same beer fermenting a couple of weeks after the first). Therefore I must lower temperature gradually so as to keep the yeast healthy and keep a good portion of them in suspension. Once in the keg I lager 12 ° beers 0 - 60 or 70 weeks because that's how long it takes to consume all the beer. This is how I am able to see the benefits of longer lagering, to observe that especially pleasing floral aroma build and ebb over time.

 

[Malticulous]

You know there are a lot of myths in brewing. Most of them are supported by science. I think it's important to remember this is an art.

Modern breweries don't just rely on professional tasters but also in depth chemical analysis. They know exactly how the product change with the adaption of high temp maturation. They even change other parameters to compensate. Dr. Bamforth talks a little about it in some of his books.

I think the grain bill and the mash have more to do with the final flavor. Lager fermentation is more about creating a clean product than it is about recreating small idiosyncrasies. I believe the lower temp maturation has always been about carbonation anyway. The higher temp is better at everything else. Personally I'm not cloning anything. I'm creating my own. No one can say I did it wrong but me.

 

[ajdelange]

You know there are a lot of myths in brewing.

Yes, I do.

Most of them are supported by science.

No they aren't. It's usually when a suspect "truism" is investigated scientifically that it is debunked. Actually, what other means could one use to debunk it?

I think it's important to remember this is an art.

Absolutely. Why do you think there is such diversity in lagering practice?

But your words seem to suggest that think some of the lagering methods in the literature lack validity. Which ones would those be? Are you saying that DeClerck is wrong and Narziß right? Ot that the notion that the traditional methods make better beer is a myth? If so remember that one cannot use the phrase "better" without stating his optimality criterion (or criteria). Mine are that the product is pleasing to me and my guests and gets a nod from the most experienced home and professional brewers. The criterion for those professional brewers is quite different: that the beer sells. As I said to one "The difference between you and me is that I don't have to make a profit". And a brewpub investor once said to me "This isn't very authentic but I don't care as long as it sells". I think I've demonstrated that it is not feasible to use the old methods any more on economic grounds. It is not 'best beer' by my definition that drives the modern brewer. It is best beer as constrained by the realities of capital limitation and customer preference.

Modern breweries don't just rely on professional tasters but also in depth chemical analysis. They know exactly how the product change with the adaption of high temp maturation. They even change other parameters to compensate. Dr. Bamforth talks a little about it in some of his books.

Yes they do but no, they don't know exactly by any means. They can measure lots of things certainly and the largest breweries can do very detailed analysis on every batch and they can try to correlate ethyl hexanoate levels with panel preference but there are still lots of mysteries. There are simply too many degrees of freedom in brewing and in human perception for us ever to have an exact understaning. Were your hypothesis correct there would be no need for the JASBC (or any other journal). If you look at just the index of an issue you will quickly get a feel for how far we still have to go. The large breweries do, of course, have large staffs of scientists who strive to produce more marketable beer at lower capital, labor, energy and materials costs. Obviously, if quality is too poor sales will drop off but quality is not, by any means, in first place. Modern lagering practices are based on the traditional sciences certainly but accounting science has a major role too. Are you suggesting that a brewery of sufficient size to operate a GC/MS makes better beer than those made by the traditional methods in an artisanal brewery?

I think the grain bill and the mash have more to do with the final flavor.

I'm not sure you would say that if you were familiar with traditional lagering practices. Selection of yeast strain and the way it is managed have, IMO, an equal if not greater effect. If you brew two Boh. Pils with the same grain bill but use the Urquell strain for one and the Budvar for the other you will get two entirely different beers and, of course, if you buy PU and Budvar and taste them side by side they are dramatically different. OTOH if you brew two Boh. Pils using the Budvar strain but use Weyermann's regular malt for one and their floor malted malt for the other you will indeed get different beers as well but their relative qualities as lagering progresses puts one in first place, then the other before they finally become pretty close.

Lager fermentation is more about creating a clean product than it is about recreating small idiosyncrasies.

Again I don't think you would say that if you were familiar with traditional lagering. It is exactly those nuances of flavor which are attributable to lagering practices which are responsible for the diversity in those practices. The beer should be clean from the primary fermentation (lag phase at cold temperature ...). Lagering is for removal of jungbuket, melding of flavors, precipitation of phenols, reduction of VDKs, flavor maturation etc.

Personally I'm not cloning anything.

Never understood why anyone would want to. If I can make better beer than I can buy why would I want to imitate the inferior product? I guess it could be looked at as a challenge.

I'm creating my own. No one can say I did it wrong but me.

I don't think anyone is suggesting you are doing anything wrong but you do seem rather resistant to the possibility that there may be a better way. I can assure you that there is a better way (not limited to how you conduct lagering) because if there isn't that means you are at optimum (as defined by your own criterion) and that never happens. This is a good thing for the home brewer. He is constantly striving to increase the enjoyment of his product and that increases his enjoymnet of the hobby. "Better is the enemy of good enough." may have been a good philosophy for the Soviet army but is not for the home brewer.

 

[Malticulous]

I'm not saying much, certainty not as much as you. I'm not even sure if we disagree? If you really want to get historical none of this could be true. They didn't even have a thermometer. The process was formed around the environment and silly laws.

And yes you did say I do it wrong in your first post of this thread.

 

[ajdelange]

I'm not saying much, certainty not as much as you.

There's a lot to be said. It's a deep subject that has occupied the minds of brewers and brewing scientists from the time of the 'invention' of lager beer.

I'm not even sure if we disagree?

I am sure if you came over and we sat down over a couple of beers we'd find plenty to agree upon though it's likely that we would disagree on some things as well. I certainly have no problem with that. Quite the contrary in fact. It's disagreements (and uncertainties) that cause scientists to undertake investigations.

If you really want to get historical none of this could be true. They didn't even have a thermometer. The process was formed around the environment and silly laws.

Not sure what you mean by this. The environment and silly laws conspired to cause Germany and Bohemia to produce the best beers in the world (British ale fans forgive me). Scientific analysis of why they were so good fueled not only better beer but seminal contributions to medicine and related fields. The first single cell culture was done on lager yeast. pH was discovered at the Carlsberg Lab etc.

And yes you did say I do it wrong in your first post of this thread.

I'd rather keep the discussion to the principles of brewing science but here's what you posted:

I don't want yeast when lagering. When I lager I'm done with them...

To which I replied:

Then don't have them. You won't get as good a beer but you must do as you choose

If I'd wanted to say you are doing it wrong that would have read "You are doing it wrong". I sometimes assume that people understand the duality of optimality and the criteria which define it but I guess many don't. What was intended here is that the criteria for optimality were those usually associated with the home brewing community. From the megabrewer bean counter perspective the quick program is obviously optimal (or as close to it as they can get at the moment). If it weren't they'd adapt to make it more so. My goal here isn't to offend but rather to inform.

 

[Malticulous]

After re-reading all you posts there is a lot I don't agree with. I'm not going there. "Proper lagering" is taking place in all of these schedules.

"C" is what I do in the summer. It's freeking hot that time of year here so I don't have the use of the environment like I do now; schedule "F". I crash before crop though.

 

[sonex]

D and F are the schedules that I have followed but as you have shown there are a lot of ways to get to the same place. Thats whats so great about this hobby there is always something new to learn.

 

[ajdelange]

After re-reading all you posts there is a lot I don't agree with.

I guess that means you aren't the guy that gave me the 'thumbs up' for them.

I'm not going there.

I had noticed that whenever I invited you to elucidate in the previous posts you declined.

"Proper lagering" is taking place in all of these schedules.

Lagering implies long storage (the Germans used that term for some of their POW camps). Thus lagering is actually only taking place in A. Note that the diagrams themselves don't use that term but rather refer to "maturation" except in A where "storage" which is translates from the German "lager" (these diagrams come from Kunze's book which I have only in English so I can't really verify that besides which Kunze got them from another author). But as I said before I'd rather keep it to discussions based on the science of brewing that quibbling over the exact meaning of words (which is, of course exactly what I am doing here). If you are making beer which is acceptable to you that is really the most important thing. So let's just leave it at that.

 

[wildwest450]

Where did you come up with the one degree drop per day? Never heard that one before.

 

[Malticulous]

I could quote it form a number of places, but as a homebrewer working with different yeast strains, different pitch rates and different wort with out constant monitoring it would likely end with under attenuated wort or diaycetyl. It works best when the brewer brews same thing over, and over, and over again and so knows the exact gravity and exact time to start the drop in temp. You can find something close to it on Kai's site.

 

[flabyboy]

From what I have read,the slow drop in temp is so the yeast clean up the byproducts like diacetyl as they slowly drop out. The big breweries that do this method, do not do Diacetyl rests. So if you are doing a d rest, the slow drop is not necessary.

Traditional lagering happened in caves and cool places before refrigeration came around. I doubt they had the precise temp control you are talking about

 

[ajdelange]

1°/day has been floating around for a long time. That's the value I have been using for so long (without much regard for whether it is a Fahrenheit or Centigrade degree) that I have no idea where I first saw it. A reference that mentions it and which is readily accessible to home brewers is White and Zainasheff's "Yeast". See p 115

 

[ajdelange]

big breweries that do this method, do not do Diacetyl rests.

I doubt you will find many big (or small or medium) breweries that use this method any more. As we've discussed previously in this thread the economics don't permit it and the average consumer wouldn't notice the difference. I wonder about Pilsner Urquell though. As recently as my last visit there (which wasn't that recent, truth be told) they were still doing decoction mashing and traditional lagering. I wonder if they still do. They had the plant so it wouldn't be question of having to raise the capital for it but modernization, maintenance, increased capacity etc. may well have driven them to disband both of those practices. I think most agree that PU isn't what it used to be. If you want a triply decocted, traditionally lagered beer you are probably going to have to brew it yourself.

So if you are doing a d rest, the slow drop is not necessary.

I wonder about that. Crash cooling yeast puts them in distress. They produce "shock proteins" and release esters. This is OK in ale brewing where esters are desired but not in lagers. Looking at the various profiles fom Kunze (#32) the temperature drops are pretty precipitous. I guess the idea would be to separate the yeast as quickly as possible when one of these programs is being used and, of course, that is consistent with getting the beer out the door as soon as possible. I suppose the message to home brewers is that if you use one of these schemes you need to get the yeast out tout suite.

 

[flabyboy]

Interesting. Never knew that crash cooling could cause off flavors. First time I have heard that. I usually rack off my yeast when lagering anyway, but I like to crash cool an IPA I have dry hopped to get the hop material down in the trub