Lager fermentation process question

[glutarded-chris]

Hello All! I have been brewing ales for years, mostly pale ales, and have decided that I need to get into lager territory. I did some research on the forum and consulted my handy How To Brew book by Palmer, but still have a couple of fundamental process questions that I am hoping to get experienced input on before subjecting myself to my own blind testing

I can control temperature fairly well as I have a controller on a commercial freezer for a fermentation vessel.

Basic process is to:

1. Primary fermentation at about 50F
2. Raise to ~60F for a couple of days for a Diacetyl rest
3. Lower to 32-35 F for lagering for a couple weeks to a month

First big question comes at step 3. I keg my beer so I see a lot of debate:

a. let sit on the trub in the primary for the lagering phase (some say as long as the lagering phase is not more than a month)

b. rack to a secondary for the lagering phase and then keg after that (presumably this allows any sulfur gas to be pushed out of the airlock)

c. after step 3 is complete, cold crash with or without finings to 32-35F and then immediately transfer to a keg for the lagering phase

For simplicity of process and less things to clean, I would really like to do a. or c. for step 3. I read that with lager yeast, you get sulfur compounds that come out. What I don't see is if transferring to a keg after primary holds the remaining sulfur compounds in suspension of if the yeast cleans them up somehow. Is it necessary to allow the sulfur gas to vent in the lagering phase?

For those that transfer to a keg after primary, do you blow off or purge the top of the keg periodically to release whatever sulfur gas?

 

[tgolanos]

If I were you, I'd do A. The less transferring, the better. I've let beer sit/lager on top of a yeast cake for 2 months without issue- I think you'll be fine. While I do use secondaries, I tend to only use them if I know I'm going to need one of my buckets for another brew or to bottle.

As far as sulfer goes, I've always found that by the time I bottle, the yeast has either cleaned it up or secondary has given it time to dissipate. I've never purposely vented any, though.

 

[jmcquesten]

Hello All! I have been brewing ales for years, mostly pale ales, and have decided that I need to get into lager territory. I did some research on the forum and consulted my handy How To Brew book by Palmer, but still have a couple of fundamental process questions that I am hoping to get experienced input on before subjecting myself to my own blind testing

I can control temperature fairly well as I have a controller on a commercial freezer for a fermentation vessel.

Basic process is to:

1. Primary fermentation at about 50F
2. Raise to ~60F for a couple of days for a Diacetyl rest
3. Lower to 32-35 F for lagering for a couple weeks to a month

First big question comes at step 3. I keg my beer so I see a lot of debate:

a. let sit on the trub in the primary for the lagering phase (some say as long as the lagering phase is not more than a month)

b. rack to a secondary for the lagering phase and then keg after that (presumably this allows any sulfur gas to be pushed out of the airlock)

c. after step 3 is complete, cold crash with or without finings to 32-35F and then immediately transfer to a keg for the lagering phase

For simplicity of process and less things to clean, I would really like to do a. or c. for step 3. I read that with lager yeast, you get sulfur compounds that come out. What I don't see is if transferring to a keg after primary holds the remaining sulfur compounds in suspension of if the yeast cleans them up somehow. Is it necessary to allow the sulfur gas to vent in the lagering phase?

For those that transfer to a keg after primary, do you blow off or purge the top of the keg periodically to release whatever sulfur gas?

Here's what's been working well. Primary fermentation for about a week to 10 days. Raise temp for diacetyl rest for a few days. Transfer to keg. Lower temp for lagering and lager for 2 to 8 weeks (while carbonating). Inject gelatin solution into keg through gas post and let sit for a few days. Transfer to serving keg and enjoy crystal clear lager in as little as 5 weeks.

This all assumes that you're making a massive starter and have use of multiple kegs. You could also transfer to keg with a little bit of active fermentation left, but that works best with a spunding valve.

 

[glutarded-chris]

Here's what's been working well. Primary fermentation for about a week to 10 days. Raise temp for diacetyl rest for a few days. Transfer to keg. Lower temp for lagering and lager for 2 to 8 weeks (while carbonating). Inject gelatin solution into keg through gas post and let sit for a few days. Transfer to serving keg and enjoy crystal clear lager in as little as 5 weeks.

For lagering in the keg, do you open the relief valve every now and then to purge any sulfur gas that collects? Or do you think sulfur affect at this stage is minimal or that it does not collect in the head space like I am assuming?

Some have stated that they use the gelatin fining during the cold crash in the primary after the diacetyl rest. They leave it in the primary for a few days to let the gelatin do its thing and then transfer directly to the keg for lagering/serving. Risk there is I guess that any additional clarification in the keg sits in the bottom.

 

[Duffman870727]

Keys to good lager are temp control and clarification. There is no need to let it sit for months on end, that is the old way to get the beer crystal clear before modern filtration techniques were developed.

My process is 7-10 days at 55F, remove from chest freezer to a basement area that is 60-65F (or just bump up the temp controller in summer). I let it sit at the warmer temp for 2 weeks, then back into the chest freezer for cold crash at 32F. I add gelatin at 12-24 hours into cold crash, let clear for 5 days, rack to keg. It is drinkable as fast as you can carbonate at this point, you might get a little sediment in the keg but that's pulled off in the first pint and you generally don't pick up anymore until the last drop is sucked out at the end of the keg.

Certain yeast strains produce more sulpher than others, I find that the 2 week warm rest is plenty to allow the sulpher to off-gas, then it's just a matter of clarifying and carbonating the beer.

 

[McKnuckle]

This is my technique, foolproof so far (knock wood), using a Cornelius keg as both a primary fermenter and lagering/serving tank. The beer is never transferred or exposed to O2 after pitching yeast.

Drain wort to a keg equipped with a floating dip tube, allowing at least 0.5 gallons of headspace (i.e. 4.5 gal in a 5 gal corny, 2.5 in a 3, etc.). Attach a blow-off tube to the gas post, venting into a jar of Star-San.

Hold at 50ºF for five days, then begin raising 2º per day until 60º is reached. That brings you to 10 days. Hold at 60º for 2-3 days. At this point, fermentation is slow, but usually still visible in the blow-off jar. Remove the blow-off tube and allow remaining CO2 to build inside the keg. Drop temp back to 50º until two weeks have elapsed since pitching yeast.

At the two week mark, move the keg to keezer at 40º, hook up gas at 12 psi, and allow to lager for 2 weeks before tapping. Total elapsed time is thus 4 weeks. Beer will be clear and carbonated at this point. Within one more week, it will typically go from great to awesome, assuming you did everything right!

 

[Qhrumphf]

I like to pitch at 48F, ferment at 50F until 50% done (usually 2-3 days), free rise to 55 until 75% done (5-7 days), free rise to 67. When I'm 1°P above FG, cap and set spunding valve to 15 PSI. I'll let it stay there until it's both completely done and clear of diacetyl, harvest/drop the yeast, and then 5F per day down to 32F. 2 weeks or so, and I'll hit it with biofine and bring it back to 15 PSI. 48 hours later, package.

In your case, rack to keg and put it under pressure before you crash or ramp down for lagering. Never cold crash with an airlock or blowoff. Ever.

 

[Jag75]

I'm about to keg my first lager . I pretty much did what Qhrumphf did. The sulfur smell went away after about a week or so. Would kegging it and leaving at 38 degrees be considered cold crashing?

 

[McKnuckle]

It would be considered lagering!

Since 38° or thereabouts is serving temp, it’s basically the beer’s final resting place. Keg, set aside, hook up gas, and wait. Then tap and drink.

 

[Jag75]

What temp is considered cold crashing?

 

[glutarded-chris]

Good discussion here! Thanks everyone!

Never cold crash with an airlock or blowoff. Ever.

Agreed. When I cold crash I have a bladder/bag attached to the carboy or conical that I purge and fill with CO2. As it cools it pulls the CO2 in rather than pulling oxygen in.