First lager

[bwarbiany]

Okay, either tonight or tomorrow, I'm making my first lager, a 1.054 OG Oktoberfestbier. Here's how I envision the process:

1) Brew as normal, chill to ~43 degrees F.
2) Pitch yeast (4 packs SafLager W-34/70 in 10 gallons), let beer free-rise to 49 degrees F.
3) Ferment 2 weeks.
4) Let beer rise to 70 degrees for ~24 hours for diacetyl rest.
5) Cool to ~33 degrees F (in primary)
6) Let sit 2-3 weeks, transfer to corny kegs.
7) Continue to let sit at lagering temps for a few more weeks.

A few questions:

a) Do I need to be taking gravity readings during step #3? Some say that the diacetyl rest should occur before fermentation is 100% complete (i.e. when 80% of your gravity drop has been achieved). Obviously this means that step #3 could be shorter or longer if I'm actually basing it on gravity.

b) Is a 24-hour diacetyl rest enough? Note that this will likely exclude at least a day on the front end to rise from 49 to 70 degrees, and at least a day on the back end to drop the temp back down, but [in addition to the temp increase/decrease days] is 24 hours held constant at 70 degrees good enough?

c) Per my previous question, I've decided that I'll let it lager on the yeast for a short time until my kegs free up, then transfer and continue lagering in what will be my serving kegs. Does this sound normal to folks who regularly make lagers?

I trust my general brewing process, but given that this is my first lager and also going to be served at a large Oktoberfest party in 2.5 months, I want to make sure I nail it.

[brahn]

Disclaimer: I've never brewed a lager!

Now that I've got that out of the way, my understanding is that unless you're in a hurry a d-rest is not necessary at all. In ale or lager brewing diacetyl is created during fermentation and yeast clean it up as fermentation begins to slow down. This is why high flocculating yeast like Ringwood leave more diacetyl in the finished beer - they've dropped out so they can't consume the diacetyl they produced earlier. Yeast work faster at higher temperatures whether they're converting sugar to alcohol or reducing diacetyl levels, so at a higher temperature they will get rid of the diacetyl faster. There's nothing magic about the lager yeast in this regard, it's simply doing everything slower due to the lower temperature.

It was quite a while ago, but I believe BrewMasterBrad had told me that he didn't do a d-rest with his lagers, he just gave them an extra week or two at fermentation temperature. Maybe he could weigh in on this with some practical experience.

[bwarbiany]

Brent,

I read this:

http://www.homebrewtalk.com/wiki/index. ... f_the_beer

Diagram A would appear to be what Brad N. is doing. Diagram F is a traditional diacetyl rest. My understanding is that when you don't do a diacetyl rest, you need to be careful when dropping temps on the beer, lest the yeast go dormant and fail to continue diacetyl reduction. Leaving a week longer, or dropping temps very slowly, can help the yeast do their job. Apparently doing a diacetyl rest, though, with the 70 degree temp knocks the diacetyl right out very quickly and easily, at which point you can just crash it to lagering temps and not worry about it.

It seems to me that doing a diacetyl rest is the more foolproof method. Barring any negative side effects (of which I'm unaware), I can't see any reason to avoid it.

[BrewMasterBrad]

Sorry for the delayed response, but I just got back from vacation.

I don't do a d-rest at all, but I know the lager yeasts that I use very well and have figured out how long they need to stay in primary before cooling and racking. I have never used a dried lager yeast, so my methods may not work as well with what BradW is looking at. With that being said, I see nothing wrong with the fermentation schedule in the initial post. I generally leave my lagers at fermentation temp for about 3 weeks, then slowly start dropping the temp 1 degree per day until I get down to about 35F. Then I rack to my bright tanks and leave it at 35F for at least another week before racking into the serving kegs. I have found that my Vienna and Oktoberfest beers peak at about 2 months after the brew day, so your timing should be about right for serving this beer. Many brewers that do a d-rest do take gravity readings to determine when to start raising the temperature. I am too lazy to do that, so my method is more pragmatic than scientific. It works for me and that's all I really care about.

[bwarbiany]

9 days after pitching, I've dropped from 1.052 to 1.014. A bit lower than I wanted to be for the D-rest, but it was still actively bubbling (1 bubble every 3 seconds), so I think the yeast are still in an active phase.

Now the rise to ~70 degrees has begun.

I liked the taste in the sample... I think I feel good enough about this to let my wife start sending out the O-fest party invites

[bwarbiany]

You know, I hadn't thought about lagering temp much. I just assumed my fridge would be able to get there without a problem. But right now my Oktoberfest is sitting at 38 degrees, not 33 degrees, and I'm not sure the fridge will get any lower. It's a standard fridge/freezer combo, with the freezer on top.

Any ideas?

[brahn]

Unless you've got some reason that you really want to get to 33F I wouldn't worry about it...

http://www.howtobrew.com/section1/chapter10-5.html

[bwarbiany]

Unless you've got some reason that you really want to get to 33F I wouldn't worry about it...

http://www.howtobrew.com/section1/chapter10-5.html

My impression (counter to Palmer) has always been that lower is better. The online version is Palmer's 1st edition of the book -- any chance this has changed since?

Everything I've ever known about lagers is that the lagering process -- PARTICULARLY if a diacetyl rest is used, as I did -- is mainly about clearing the beer. I could be wrong, but clearing takes place faster at colder temps, does it not?

Given the situation, though, I might just let it sit at this temp for 2-3 weeks, add gelatin towards the end of that time, then move it to corny kegs 5-7 days after adding gelatin. Between 3 weeks at [now] 37 degrees and a gelatin addition, I have to think I'll have very clear beer by that time.

Edit -- by which to say I'd put the cornies back into the fridge for additional lagering, not that I'm restricting total lagering duration to 3 weeks.

[brahn]

My impression (counter to Palmer)

How dare you!?

I don't have access to my 3rd edition or any of my other books at work, maybe someone else can look it up. I was just thinking that 38 seemed like an appropriate temperature for lagering and wanted to check what Palmer said.

I agree with what you're saying about the beer clearing faster if it's colder. My point was just that you should still get good results at 38 (37 now?), so it should be safe to RDWHAHB.

[backyard brewer]

IME with lagers, colder is better, but not so much so that I'd make any real effort to go from 38 to 33* If I could get to 33, then great but if not: Meh... Have a beer.

[bwarbiany]

IME with lagers, colder is better, but not so much so that I'd make any real effort to go from 38 to 33* If I could get to 33, then great but if not: Meh... Have a beer.

Yeah, and somehow it's dropped all the way to 36 now. I think I'm fine.