Lagering Process

[Pete2501]

I'm guessing you're interested in the science of how and why though?

Yep. I believe it has something to do with colloids which was in the link i posted early. This also effects flavour stability.

Link

 

[MHB]

This is a good start
View attachment 37666
MHB

 

[Nick JD]

Urquell

So "traditional" lagering is rare, some could say defunct?

Polyclar gets me with beer in hand in a few days. Lagering is for people who like looking at beer...

 

[manticle]

"Obviously"
That or never let the beer warm up

MHB

Obvious to you with loads of experience. Less obvious to people who are still working things out.

Cheers for the info anyway.

 

[Pete2501]

So "traditional" lagering is rare, some could say defunct?

Polyclar gets me with beer in hand in a few days. Lagering is for people who like looking at beer...

Yeah nah that's not entirely true. Polyclar isn't going to drop that old egg smell out any time quicker.

I feel what you're saying but I'm still interested in the process and the merits of lagering for long periods at cold temps. I drink my APAs pretty green most of the time in about 2 weeks so I'm all for the beer being quicker in my hand. But I'd love to know more about the changes that happen when the beer is kept at those cold temps for long periods of time.

 

[pyrobrewer]

The objectives of that course don't cover the topics I've raised though.

edit: ingrish

As someone who has actually done it I have to disagree with you there!

 

[Pete2501]

As someone who has actually done it I have to disagree with you there!

You'd know best then.

I was just going from what was listed on the course outline.

By the way MHB, awesome document. Cheers for the upload.

 

[Nick JD]

Yeah nah that's not entirely true. Polyclar isn't going to drop that old egg smell out any time quicker.

I feel what you're saying but I'm still interested in the process and the merits of lagering for long periods at cold temps. I drink my APAs pretty green most of the time in about 2 weeks so I'm all for the beer being quicker in my hand. But I'd love to know more about the changes that happen when the beer is kept at those cold temps for long periods of time.

The rotten egg smell is gone for me by the time the beer's cleared with the small handful of lager yeasts I've used - and I'm used some eggy ones.

Brewing Science and Practice does cover traditional lagering. Let us know if you find some good info - when Dr. Smurto can't enlighten us there really is something mysterious about it.

 

[Roscoe]

And while you keep looking also look into the historical reasons for lagering and the modern improvements that now make it moot. This might tell you a lot.

Can you tell me a commercial example of a beer that is lagerd for traditional periods?

At Pilsner Urquell there is approximately 6 miles of tunnels under the brewery that is fairly stable at 4 deg c. These were used in their traditional brewing process. After primary fermentation they would transfer the beer into timber hogsheads then store them in these tunnels for a minimum of 3 months.

Today the beer is lagered in temperature controlled stainless vats, unfortunately the tunnels are no longer used for commercial production.

Here are a couple of photos of the tunnels. Sorry about the quality - I'm definately not a photographer.

Cheers Roscoe

 

[drsmurto]

The rotten egg smell is gone for me by the time the beer's cleared with the small handful of lager yeasts I've used - and I'm used some eggy ones.

Brewing Science and Practice does cover traditional lagering. Let us know if you find some good info - when Dr. Smurto can't enlighten us there really is something mysterious about it.

Here's a link to an article from Brewing Techniques that goes into some of the history and modern practises at Urquell - Link

Article was written in 1997 and according to it Urquell was still lagering their beer for 35-40 days and still doing triple decoctions. Whether that is still true in 2010 is up for debate. I agree that extended lagering isn't something that is going to make the bean counters happy. Will it produce a better beer though? I am in the yes camp.

I have never studied brewing other than reading a few books and various forums.

My uneducated opinion on lagering (based on reading and some experience) is that its not just for clarifying the beer. I use gelatine and polyclar routinely in my process because i believe the removal of yeast and proteins improves flavour as well as beer stability. The lagering process IMO also improves the flavour as it gives time for the malt and hops to 'meld' together for want of a better term. To my palate the beer is better balanced, no sharp hop flavours, esters etc.

It may not be necessary but its how i do it as i have the time, the fridge space and i am interested in the process and producing the best beer i can.

My 2 c so take it with a grain or 2 of the relevant brewing salt
DrSmurto

 

[Pete2501]

The rotten egg smell is gone for me by the time the beer's cleared with the small handful of lager yeasts I've used - and I'm used some eggy ones.

Brewing Science and Practice does cover traditional lagering. Let us know if you find some good info - when Dr. Smurto can't enlighten us there really is something mysterious about it.

Coolies, I'm reading through chapter 15 now.

 

[MHB]

If you really want a good book on lager, the new 4^TH international edition of Kunze should be out next month.

Probably the best text on lager production available

VLB-Berlin .org

MHB

 

[Pete2501]

Do you know if it covers the more scientific parts of the process or is it a history lesson with examples of current brewery processes?

 

[MHB]

I think it's the standard text book for VLB (Berlin Brewing University), I have the older 3^Rd edition and the 4^Th on order.

It covers both the science and practice of lager brewing better than any other book I know of, I'm sure there are lots of other brewers here who know the book well maby some of them could comment; but for mine it's about the best investment you can make.

MHB

 

[unrealeous]

If you really want a good book on lager, the new 4^TH international edition of Kunze should be out next month.

Probably the best text on lager production available

VLB-Berlin .org

Its finally out....

 

[technoicon]

not really sci so much but experience with my 2 lagers.

my first i didnt raise the temp to 20 C (diacetyl) at all just lagered for 2 weeks. was nice but had some weird favours very small though.

the second i did a diacetyl rest. we drank most of it with no lagering at all but wasnt to nice and had the funny smell. But after just 5 days i couldnt stop drinking it wasnt very clear but really tasted awesome.

basically my second tasted better after 5 days than the first did after 2 weeks. they were pretty much the same beer, but different alc content.(first 3-4, second 5.2)

i'll be repeating my second run a fair few times i think.

cheers

 

[BjornJ]

Here's a link to an article from Brewing Techniques that goes into some of the history and modern practises at Urquell - Link

Article was written in 1997 and according to it Urquell was still lagering their beer for 35-40 days and still doing triple decoctions. Whether that is still true in 2010 is up for debate. I agree that extended lagering isn't something that is going to make the bean counters happy. Will it produce a better beer though? I am in the yes camp.

I
DrSmurto

Interesting to read about how it happens with the "real deal", especially that they
-pitch the yeast at 4 degrees
-slowly raise the temp to 9 degrees
STOP fermentation when FG is 1.015.

I did not know that lager yeast would ferment that low, or that they would actually kill off the yeast before it was done.
Mmm, will have to buy some Pilsner Urquell on the weekend to quality control the process


thanks
Bjorn

 

[rendo]

Great Idea BjornJ, I have to admit I was thinking the exact same thing

rendo

Interesting to read ....
Mmm, will have to buy some Pilsner Urquell on the weekend to quality control the process


thanks
Bjorn

 

[BjornJ]

Great Idea BjornJ, I have to admit I was thinking the exact same thing

rendo

Hehe, we have to take our research seriously, Adam!



Bjorn

 

[Thirsty Boy]

If you want the chemistry... well Kunze has it, Briggs has it - you'll just have to search it out or buy it because I cant be buggered writing it all out... but it fundamentally boils down to this. Stuff drops out of solution when beer is cold.. the colder it gets, the faster stuff drops out.

Iso alpha acids drop out of solution, chill haze forms and falls to the bottom - slow chemical reactions occur, most of them resulting in things becoming less soluble. Time and gravity mean that after a month or two... those things are at the bottom of the tank and can be left behind, not that it matters if you are filtering... just don't let the beer get warm.

Extended lagering - more than a couple of weeks - is primarily about chill haze. Letting the stubborn stuff form and fall. If you can get rid of it without the time... then you don't need to worry. Also the lowering of bitterness due to alpha acids precipitating out... less bitterness makes the beer seem smoother.

Yeast will be micro active at cold temperatures.. but really they are mostly part of the game earlier on. After a couple of weeks, when you are into teh long term cold cold (0 or -1C) storage.. its colloidal stability they are chasing.