Excessive diacetyl rest for a lager?

[jufrey18]

Just a little background info:

I’ve got a lot of time under my belt with ales but this is my first go around with a lager. That being said I decided to branch out and use a local yeast lab here in TX for the liquid lager yeast. They are highly reputable and a lot of local craft breweries use them. About an hour after I pitched the yeast I received a call from the lab. They apologized and said they gave me too much yeast in the bag. I thought it seemed slightly large but I’ve always been told with lagers you must pitch a lot more yeast so I honestly didn’t think about it much. They said they recommended I drop the fermentation temp to 50 to keep it from “fermenting too fast”

originally I was told to pitch at 60-64 until there was active fermentation then drop to 50-54 until fermentation slowed down dramatically then raise to 66-70 for a 24-48 hour diacetyl rest then test for diacetyl and if satisfied rack to secondary and lager for several weeks.


My question is this. Even at 48-50 the thing fermented super fast. I warmed to 68 after 5 days . Once at rest temps I did my diacetyl sample at 36 hours and it was aweful. Like straight up melted butter. Slightly better at 48 hours and now I’m at 72 hours and it’s vastly better. Like 95% better than sample 1 at 36 hours. How long is too long to keep the diacetyl rest going? I’d like to clean it up a little more but should I be worried about keeping it to long at this temp? I covet any advice you all would have on this. TIA

 

[josephort]

As I understand it, cool fermentation is only necessary during the beginning of fermentation- most off flavors that you're trying to avoid, including diacetyl, are produced by the yeast during their lag and growth phases. You want to start the diacetyl rest during the stationary phase to help the yeast clean up, and at this point you're unlikely to have additional off-flavor production, so prolonging the rest shouldn't be a problem.

My typical lager schedule is to ferment cold until fermentation is ~75% of the way done, which is usually about a week, and then let it sit at room temperature for ~2 weeks, then cold crash. I've never had noticeable diacetyl, even after microwaving a sample, and I've read posts from others who do a similar schedule succesfully. That said, I've only brewed a handful of lagers and I'm typically pretty laissez-faire about this sort of thing, so if someone more experienced wants to correct me that's fine.

 

[Vale71]

I'd wait two more days starting when you cannot taste diacetyl any more. The reason for that is there could be precursors in the beer (which we cannot taste) that haven't turnde to diacetyl yet. So, lacking a lab to measure them, time and patience are your only friends.

 

[Northern_Brewer]

So, lacking a lab to measure them, time and patience are your only friends.

Or a diacetyl force test - take two samples, warm one to 60C (140F) for 15 minutes, then cool it and taste them side by side. If you can't detect diacetyl in the warm sample, you're good to go.

These are a good introduction :
https://beerandbrewing.com/off-flavor-of-the-week-diacetyl/
https://beerandbrewing.com/hunting-for-diacetyl/

 

[Dland]

I've never noticed any ill effects from running the D rest a few extra days. Once in a while I raise the temp a little late in fermentation, yeast activity wise, and I'll run the D rest longer to make sure it cleans up.

 

[Cyclman]

Too long > too short, as with many brewing topics.

 

[couchsending]

Pitch enough yeast and ferment it cold and you won’t get diacetyl, don’t need to do a diacetyl rest, and end up with a more flavorful/aromatic beer.

 

[jufrey18]

Update........... first batch turned out ok. A slight diacetyl flavor but all in all pretty darn good. I just completed a second batch, this time pitching the correct amount of yeast. It turned out excellent. So good I have 5 neighbors begging me to ramp up productions for next go around. The donation jar will be in my garage if they are willing :-D Thanks for all the advice

 

[Duffman870727]

I am blind as a bat to diacetyl, I suppose I should consider myself fortunate. My lager process is 5-7 days at 50-55F, about when I see active fermentation start to taper off, then warm up to ~65F and hold 2 weeks before cold crash and fining. With a fast carb method, I've had bright clear, clean and crisp lager grain to glass in 28 days. Extended lagering times are really just a carry-over from the olden days when they had no other means of clarifying the beer. A lager is ready to drink as soon as it hits terminal and cleans up the diacetyl, you just need a way to clarify it (ie filter like the pros, or use finings).

 

[couchsending]

I couldn’t disagree more with everything you just said.

 

[Beerwildered]

I couldn’t disagree more with everything you just said.

And yet you used so very few words.

 

[Vale71]

A lager is ready to drink as soon as it hits terminal and cleans up the diacetyl, you just need a way to clarify it (ie filter like the pros, or use finings).

Diacetyl is probably not the only thing you are blind to.

 

[Duffman870727]

I couldn’t disagree more with everything you just said.

Diacetyl is probably not the only thing you are blind to.

Care to elaborate, fellas? Once the VDKs are scrubbed up by the yeast, what else is there for them to do? Autolyze? You like the character of exploded yeast cell in your beer? How long do you think Budweiser sits in tank for? You're insane if you think they hold it for 3 months... You might not like Bud, but you surely cannot say they put out a technically "flawed" product.

Disagree if you like ¯\_(ツ)_/¯ but I've won gold and silver with first time entries in competition with an American light lager and German pils, respectively, using my methods. The light lager was brewed June 17th/2018, removed from the lager chest June 22nd to warm up and complete fermentation, cold crashed and finned July 8th, notes are lost on when it was transferred to keg and carbonated, but my bottles were submitted to the competition on July 19th/2018 (packaged from keg with beer gun). Bam! Gold medal winning beer. Sure, sure, belittle my palate, I must be some hillbilly that thinks swampwater tastes great But if I could fool a panel of BJCP judges, then maybe, just maaaayyybe, I know something about brewing that you don't

Just because "That's the way we've always done it", doesn't make it right or the best way Science, research, and technology is a wonderful thing

 

[couchsending]

If you’re warming up your beer to do a diacetyl rest then yeah long lagering times aren’t necessary. If you’re goal is soulless boring lager beer then yeah single infusion mashing with some 2 row, fermenting at 53, bumping it to 65, crash cooling, fining, and force carbonating are the way to go.

If you care to make delicate yet full bodied, flavorful lager beer with better mouthfeel, long lasting head, and just overall a better drinking experience then there are much better ways to do it.

All about personal preference.

Using Budweiser is a poor example. Their brewing methods are 100% margin based and have to be with the price their beer is sold at.

There is a reason cold fermentation, natural carbonation, and long lagering times are performed by the best lager breweries in the world. Even Decoction for that matter.

 

[Vale71]

Care to elaborate, fellas? Once the VDKs are scrubbed up by the yeast, what else is there for them to do? Autolyze?

Disagree if you like ¯\_(ツ)_/¯ but I've won gold and silver with first time entries in competition with an American light lager and German pils, respectively, using my methods.

Color me totally unimpressed. The swill that at times makes it to first place in these competitions would make me cringe with shame, if I were a judge at said competition.

BTW, Bud is indeed a flawed product but they don't care as long as their sales numbers and profit margins are good. They're in the market to make a profit, not to educate the consumer. Citing them as some sort of gold quality standard is, quite frankly, simply ridiculous.

 

[Duffman870727]

Wow... You'd think brewers would be a cool, easy going bunch... what a pair of pretentious, presumptuous ding-dongs the two of you are. Insinuating my beer is swill? I don't have any idea what I'm talking about? Making such a statement with nothing to back yourself up indicates to me that, you, in fact, are the one(s) lacking knowledge.

Please, indulge me, educate me, science me. Tell me, very specifically, what chemical/biological reactions occur during extended "cold aging" that serve to produce lager beer in the only "acceptable" manner?

Guys, you've never even tried my beer. To pass such harsh judgement... All I can say is I have a great crow marinade recipe for you. I'm a very good brewer and I'd bet real money you'd enjoy my beer if served to you blind, without the bias that a quick turnaround couldn't possibly result in a high quality product. I detect a hint of jealously that I am able to turnaround the brew much faster than you can, and I feel sorry for you that you waste so much unnecessary time waiting for your beer to "lager". I don't think you realize how much skill it takes to minimize production time, everything from yeast propagation to brewhouse acumen to cellaring has to be spot on, no room for error or you'll have to wait and hope the brew fixes itself with long aging.

There is a reason cold fermentation, natural carbonation, and long lagering times are performed by the best lager breweries in the world. Even Decoction for that matter.

The absolute necessity of cold temp is debatable, and strain dependent. For the sake of argument, cold temp during the acceleration phase of yeast growth is key to suppress VDK, ester, and fusel production (for those strains that cannot perform cleanly at higher temp). After this phase, about 2/3rds of the way through attenuation, it is no longer necessary to maintain cold temps, the yeast are done outputting these "off flavor" compounds and benefit from warmer temps to enhance re-uptake of VDK. Once terminal gravity is achieved, and the beer is clear of VDK, the yeast are done and begin to enter dormancy. They flocculate, live off their glycogen reserves, and eventually die. What does letting your beer sit on dormant/dying yeast for months do to enhance the product? I can tell you that the yeast is removed from the cone of the fermenter in professional breweries ASAP, it is an extremely stressful place for them to be (your little 5 gallon carboy is nothing in comparison).

Natural carbonation is done for reinheitsgebot compliance, they cannot buy a tank of CO2 from Praxair and force carb. They can, and do, recover CO2 produced "naturally" from fermentation, store that in a tank, and use it to force carb as all other breweries do with purchased CO2. Other breweries might krausen, or cap fermentation at a certain point above terminal. Please recognize this is not done because it results in a superior lager, it is strictly for reinheitsgebot compliance.

Decoction... You know why that was done? Early in the history of brewing malt was undermodified, so decoction helped brewers gain better extract out of this poor quality malt. Also, it was a method of temperature control before the thermometer was invented. Using a known quantity of malt, water, and boiling water, brewers could achieve the appropriate temperatures. Pulling a decoction, boiling it, and adding it back provides a consistent temperature increase. Flavor wise... just add some melanoidin malt and skip the ordeal.

Don't read to much into the Bud example, I don't care for their product either, but I have incredible respect for the quality control that goes into producing that product so consistently from multiple facilities around the world. They could easily brew world class pilsner, but that's not their business model. A lot of people like what they make... so they give it to them and squeeze every bit of profitability out of it that they can. No, their product is not flawed, it is spot on to style, every time, or people get fired. You just don't like it, there is a difference.

Couchsending... what was that about long lasting head? This photo is from July 22nd/2018. With 40% adjunct, I must be doing something right in the brewhouse to maintain such great head retention in my light lager



I only brewed the light beer just to prove to myself I could, German Pils is more my style



Might as well enjoy that German Pils while knocking out 10G of Czech Pils



Cream ale is very refreshing on a brew day



It's been 10 days, time to chill down my recent German Pils brew, fin it, and get it carbing in the keg. Basically, the 2 week set and forget slow carb in the keg is all it really needs for "lagering" time. I dunno guys, I prefer what I brew to anything I can buy commercially. Either every (lager) brewery around me and the imports we get suck (therefore making my "swill" better by default), or I actually know what I'm doing.

 

[couchsending]

I don’t need to taste your beers. I’ve brewed plenty of lager beers using both methods. Slow and low is far superior in aroma/flavor/mouthfeel IMHO.

And no offense but that’s nothing when it comes to foam.

The reason to not increase the temp has nothing to do with the esters or aroma created by the yeast.

How many beers have you naturally versus force carbonated? Or even split a batch and force carbonated and krausened the other? The difference is obvious and it’s not German purity law based.

How many commercial beers brewed on the very traditional way have you had.. or I should say how many have you had that aren’t old as Fack cause unless you’re going to very specific breweries in the US almost every import here is so old it doesn’t matter.

How many Decoction brews have you done? How many different Decoction profiles have you tried? I totally understand the reason why it was done but even with well modified malt it still has a flavor impact on the final beer that can’t be replicated by melanoidin or Munich or whatever.

The reason the fast fermentation, short lagering, filtering, force carbonation method is employed by 85% of the lager beers commercially made in the US is straight up cost based. Not cause it makes better beer.

 

[Northern_Brewer]

Decoction... You know why that was done? Early in the history of brewing malt was undermodified, so decoction helped brewers gain better extract out of this poor quality malt. Also, it was a method of temperature control before the thermometer was invented. Using a known quantity of malt, water, and boiling water, brewers could achieve the appropriate temperatures. Pulling a decoction, boiling it, and adding it back provides a consistent temperature increase.

Without wanting to get too embroiled in this, although the above is the conventional wisdom, Lars Garshol has shown that farmhouse brewers in Norway can hit their temperatures reliably just through experience, without thermometers or decoction. Don't underestimate the power of experience.

And you won't be able to persuade a Brit (and paid-up CAMRA member...) that the quality of carbonation in your glass is the same from force-carbonation and cask-/"natural" carbonation....