Confused about lagering times and temperatures

[galactaphonic]

Hi all,

I hope this isn't a question that is constantly asked but... I'm confused about the lager process as there seems to be a lot of contradictory information out there. I think I get the primary fermentation part - roughly two weeks at about 10°C then a diacetyl rest - but I'm not 100% sure what to do next.

Here's some of what my research has turned up:

• Palmer says "Nominal lagering times are 3 - 4 weeks at 45°F, 5 - 6 weeks at 40°F, or 7 - 8 weeks at 35°F".
• Wyeast say something different. What Palmer calls "lagering" they seem to refer to as secondary fermentation and "secondary fermentation can take from one to three weeks at temperatures starting between 39-41°F (4-5°C)". After this secondary fermentation comes the period that Wyeast call lagering or cold conditioning, is "generally in the range of 33-34°F (1-2°C)", and a "lagering period of one to four weeks is typical."
• In the latest BYO magazine in the Style Profile section, Jamil Zainasheff says to finish all active fermentation at 10°C before doing a period of cold conditioning at near freezing temperatures for a month.
• Then there's this guy with a very helpful step-by-step guide where he says to lager it at 45°F for 6 weeks.

So far I've only finished one lager and it turned out fairly ester-y. I must say I'm not particularly keen on making all that effort if I'm only ever going to turn out substandard lager.

Can anyone help me link all this advice together?

 

[MHB]

Couple of things, I for one couldn't be arsed converting from silly systems to metric, please post in metric.
This is from Kunze which is holy writ when it comes to Lager brewing

- - - Being SG
___ Thin Being Diacetyl in mg/L right hand scale
___ Thick being Temperature in oC from scale on left
Up Arrows, being where yeast/trub is cropped in days from pitching

This is the simplest temperature time profile for lager, it presupposes very large (by home brew standards) yeast pitches and pretty tight temperature control.

The whole point of lager brewing is to make beer with out too many sulphur based flavours, the cool fermentation reduces these.
Cleaner flavoured beer, Lager yeast eats some sugars that Ale wont, lower temps also reduce ester production but you need more yeast as it is working slower.
Lagering (literally to store from German) also called "Chill Proofing", "Cold Conditioning"... The idea being to allow tannins and polyphenols to combine (chill haze) and then give them time to fall to the bottom of the tank, to either remove them or rack the off them without allowing it to warm up. If it does warm up the chill haze will go back into solution and you will have undone all the lagering.

The colder you lager (above where the beer freezes) the faster the haze forms and the faster it falls out (relative density see Stokes law).
An old rule of thumb was seven days at -1oC, and seven days for every degree above minus one. so at 0oC we are looking at two weeks, at 2oC four and so on, that's just for the haze, flavour maturation may take longer.

Making really good lager is hard work, requires the right equipment (a fan forced fridge and a willingness to rack a couple of times at a minimum), it ties up your equipment for a long time and does demand patience, but if you like lager it can be fun and challenging.
Have fun
Mark

 

[waggastew]

Something else to consider is slowly ramping down to lager temp rather than crash chilling. Aims to keep more yeast active and in suspension. A degree a day seems the suggested rate.

 

[verysupple]

Something else to consider is slowly ramping down to lager temp rather than crash chilling. Aims to keep more yeast active and in suspension. A degree a day seems the suggested rate.

There might be a need to chill slowly and keep the yeast active if you're brewing to the reinheitsgebot - can't force carb. so you need the yeast to create the CO2 before filtering/packaging etc. But otherwise there's no reason not to follow something similar to the "holy writ" above. So long as the yeast has done everything it needs to do before you chill the beer you can chill it relatively quickly.

That said, there's been a bit of talk recently about the yeast expressing esters when heated or cooled too quickly. I did some digging in to this and it's apparently only an issue if you're chilling from fermentation temp to cold conditioning/lagering temps in less than about six hours - That's 1.67 C per hour assuming ferment temp of 10 C and CC temp of 0 C. My fermenting fridge won't manage that so I just set it to 0 C and forget about it.

 

[indica86]

I used this method http://brulosophy.com/methods/lager-method/ and it worked really well.
Possibly I can't taste anything and have no idea. There was a bit of haze, but ALL my beers suffer from that.
It was clean, crisp and lovely.

 

[manticle]

I have found a significant difference in diacetyl levels by cold pitching big active starters, warming slowly for d-rest 2/3 through ferment then chilling slowly to 1-2 degree ( as opposed to fast raise d-rest, fast drop to chill).
Pretty sure my results will improve further when I introduce pure oxygen, something I'd like to get going in the next few months.

 

[galactaphonic]

Thanks a lot for the replies people. I also found this article which tied a lot of it together for me too.

http://braukaiser.com/wiki/index.php?title=Fermenting_Lagers

My takeaways are:

• After fermentation is complete then keep at about 1-2°C for about four weeks
• Primary fermentation can be hastened by a big yeast starter
• Slowly ramping up and down temps is probably a good idea

The thing I wonder about, does the four weeks at near freezing actually do anything magical apart from just drop stuff out of suspension i.e is it really just an extended cold crash?

 

[verysupple]

The thing I wonder about, does the four weeks at near freezing actually do anything magical apart from just drop stuff out of suspension i.e is it really just an extended cold crash?

Well, in practice it's a bit like a long cold crash - but minus the "crash" - slow ramps are probably better as you now know (but that applies to CCing ales, too). But it's the same in that you just keep the beer cold for a while. It does more than just drop stuff out. The flavour usually changes along the way even after it's dropped clear. I guess chemical reactions are happening slowly.

 

[Mr. No-Tip]

All the stuff MHB said

I agree on the whole, but I don't get the fan forced bit. A chesty works just fine?

Multiple rackings is a daunting way of putting it, we're really talking about once off the primary trub and once off the lager trub. If you lager in a keg, use a bent dip tube and it's really no extra effort when you go to bottling or kegging. Unless MHB means more racking than that?

Thanks a lot for the replies people. I also found this article which tied a lot of it together for me too.

http://braukaiser.com/wiki/index.php?title=Fermenting_Lagers

My takeaways are:

• After fermentation is complete then keep at about 1-2°C for about four weeks
• Primary fermentation can be hastened by a big yeast starter
• Slowly ramping up and down temps is probably a good idea

The thing I wonder about, does the four weeks at near freezing actually do anything magical apart from just drop stuff out of suspension i.e is it really just an extended cold crash?

I love the BK article. It's what I base my lagering off. For me a big yeast starter is essential. I do two in date White Labs into 3l for 20l of lager.

 

[SnakeDoctor]

I love the BK article. It's what I base my lagering off. For me a big yeast starter is essential. I do two in date White Labs into 3l for 20l of lager.

That's still under pitching for a medium OG lager isn't it?

I thought lager starters were all up around the 5L mark?

 

[TheWiggman]

That's still under pitching for a medium OG lager isn't it?

I thought lager starters were all up around the 5L mark?

Depends on OG, batch volume, whether you use a stir plate, temp etc. I do 2.5l with a single pack for 23l of 5% and Mr Malty says that's fine. Without a stir plate it would be a different story.

Ed: actually I'm not so sure now. I just put it in Mr Malty and with a 1 month old pack of yeast -



It says I should use 2 packs of yeast (which I don't). My current practice is to do 1l to get it kicking, let it ferment out, then step up to 2.5l. From what I can tell this is an acceptable practice.

 

[slcmorro]

That's still under pitching for a medium OG lager isn't it?

I thought lager starters were all up around the 5L mark?

From what I understand (and I am by no means an expert), it's still better than just dumping in a sachet/pack of yeast and hoping for the best. I collect the first runnings of almost every brew I do, and it sits refrigerated in a sanitised mason jar (1L), and then to that I add yeast be it liquid or dry. After 3 days (not scientific, I know) I usually dump the lot minus the decanted top layer of beer into a fermenter or if I have done another brew in the meantime or have DME available, I add more wort/DME to the mason jar for a further 3 days.

Absolutely no idea how many cells will be in there by the end, but I do know there will be more than when I started. I also taste the beer on top before pitching, to ensure the yeast is un-compromised.

 

[DJ_L3ThAL]

From what I understand (and I am by no means an expert), it's still better than just dumping in a sachet/pack of yeast and hoping for the best. I collect the first runnings of almost every brew I do, and it sits refrigerated in a sanitised mason jar (1L), and then to that I add yeast be it liquid or dry. After 3 days (not scientific, I know) I usually dump the lot minus the decanted top layer of beer into a fermenter or if I have done another brew in the meantime or have DME available, I add more wort/DME to the mason jar for a further 3 days.

Absolutely no idea how many cells will be in there by the end, but I do know there will be more than when I started. I also taste the beer on top before pitching, to ensure the yeast is un-compromised.

I've only just started with the Yeast book by Chris White, but AFAIK, doing a smaller starter as you described might actually be detrimental as the inoculation rate is very low, so there is no room for growth given you have so many cells in the yeast vial. It's more of getting that balance right rather than a small starter or even going to a huge starter (ie. Straight into full batch size, which would then be stressful for the yeast).

But the crux of what i have taken from it so far is that you are far better pitching two vials (lager) straight into your 23L batch than you are in a 1L starter and then into 23L. As you essentially set the yeast straight into sugar eating mode and then when dumped into the full batch they need to switch back to growth phase. Balancing the starter size with the amount of yeast you have ensures correct amount of growth so that when in the main batch the yeast won't be stressed out and can just get on with the job in a clean fashion.

Bottom line is you need to read and understand it all, more so than going off a set few dot points people on here kindly share, as it's not always the entire picture.

 

[rude]

The thing I wonder about, does the four weeks at near freezing actually do anything magical apart from just drop stuff out of suspension i.e is it really just an extended cold crash?

Funny you should say that Galactaphonic because the other day I had a munich dunkel brewed with a wyeast lager yeast
It was brewed with a williamswarner unit at my local LHBS it was very nice
The bloke told me that it was drinking at 13 days ofter fermentation due to it being under pressure clear as a bell
Ales only 7 days problem was the price of the unit
This got me thinking along youre lines above as well
Just thought I'de share but no idea on lagers really never brewed one but it is on the cards good thread for me cheers

 

[MHB]

Drifting slightly off topic, but yeast management is integral to making good lager, so perhaps not too far OT.
Ideally we need a lot of health yeast if we want to pitch cold, unfortunately a lot of the methods mentioned here may give you a lot of yeast but I would question its health. One of the vital ingredients in yeast propagation is Oxygen, without the right balance of O2 and other nutrients the yeast can be very stressed and can produce beer that is seriously flawed.

Make a special starter wort at about 1.040 (give or take), use the recommended amount of nutrient, and aerate to 10ppm with O2. Starters should be stepped up 10X in volume and you should see a 6-8 fold increase in the population at each step. Do the numbers, work out how many cells you need and what you think you are starting with that will tell you how many steps you need. I wouldn't assume the maximum population increase (I use 6X) as the danger of over-pitching is dwarfed by the problems caused by under-pitching .
Personally I like to run the yeast through its full life cycle, Pitch, allow to complete fermentation and settle out, remove the top layer and add more well aerated wort, as many times as necessary to get the population I want.

It might sound a bit tedious, but that is what it takes to make really top quality Lager. Some time ago there was an article by the head brewer at Budvar that said they pitched 5L of heavy yeast crem/Hl, works out to about 64 smack packs in 20L, I don't seriously expect any home brewer (myself included) to have those sort of pitches available, but more is better when it comes to pitching lager yeast.
Mark

 

[GalBrew]

I agree 100% with MHB on pitching rates. Very important to pitch the appropriate amount of yeast (use a calculator) for lagers to be clean. That and an appropriate shot of oxygen. I can't see how you can make a clean lager without at least those two things.

 

[TheWiggman]

With regards to O2 Mark I don't have a dedicated canister (yet). To address this I run the stir bar hard - as in, making sucking noises with a big vortex - for 10 mins after adding boiled DME/water at 1:10 to try to introduce as much as possible. Is this a decent alternative?

And based on your comments I should pitch the fresh yeast into a 250ml starter to begin with, and then to 2.5l.

 

[manticle]

You need to oxygenate the main wort as well as the starter wort.

 

[rude]

So MHB or anyone having a play around with some yeast calcs here Mr Malty & Yeastcalc ( has the step calc) for 25L 1050 lager using a stir plate
Mr malty says 463 billion cells for current date you need a 5.14 Litre starter using 1 pack wyeast
so only have 5L erlenmyer flask so go to step calc
This calc for the same above says 464 billion cells using the zainesheff stir plate so use the step1 you need 1.5 L
step 2 another 1.5 L after fermenting ccing & draining to give you 468 billion cells
Assuming I have used nutrients o2 would this method be satisfactory & why only a total of 3Litres in the step up
compared to 5 Litres in single
Hope I'm not too off topic cheers

 

[DJ_L3ThAL]

You cant do a 1.5L, remove the top layer and add another 1.5L to the freshly grown yeast population. Youll get minimal growth. Each step needs to INCREASE in size.

E.g. 10mL yeast into 100mL wort. Then resultant yeast into 1L etc. Each step needs to have the balance between amount of yeast and volume of wort known as the inoculation rate to maximise the amount of growth you get whilst not stressing out the yeast.

A good rule of thumb example would be one reasonably fresh white labs vial (50% viable) straight into a 3L starter (on a stir plate) wort for a 23L batch at 1.050. This would be a growth factor of 8.9 and result in 493 billion cells wherr the batch needs 427 according to mr malty.