Timing of Lager Brew sesh

Hey all,

Looking for some feedback on those who have done extensive lager brewing with good results. I’ve brewed a few lagers before, but have generally just thrown the fermentor in the cold winter garage after brewing and let it go. They came out decent, but I want to do one and monitor the gravity, possbily conduct a short diacetyl rest, and then slowly chill down to lagering temps (i have a fermentation fridge now).

About how long would you say it has taken a typical batch (1.055ish?) to go through primary fermentation? At what point (in days or weeks) would you conduct a diacetyl rest? These would of course be estimates as each fermentation would behave differently.

My issue is that I currently only have a two week window to brew and ferment before I leave for vacation for another three weeks. I don’t want to be on vacation during the time I’m supposed to be conducting a diacetyl rest and lagering. I also dont want to wait another couple months to brew this if I dont have to.

If I pitch a big starter into a fully oxygentated wort, is it reasonable to expect to make it through primary fermentation, a diacetyl rest, and then lager within a two week period?

The flip side is that I brew and just keep it in the primary for 5 weeks, but that kind of defeats the purpose of monitoring fermentation and conducting a D rest.


It seems like there is contrasting opinions about when to do the d-rest. I don’t know, I’m only on my second lager but I fermented down to 1.018 and then brought it upstairs for a rest and left it there for a week because I was out of town. In Chris White’s Yeast book (p 113) he mentions several methods in one paragraph saying that you can do it:

at terminal gravity (not ideal)
within 1-5 points of terminal gravity
throughout the final 1/3 of fermentation
or at terminal gravity by adding back unfermented wort (kraeusening)

I think it’s kind of one of those things that you figure out for yourself.

My usual procedure for fermenting a lager is:

Pitch around 45-50F
Ferment for 10-14 days
Slowly raise temp about 1 degree a day until it gets to 64F
Leave it at 64F for a day or two.
Drop the temp down to 35F for largering. Minimum of 4 weeks, upwards of 3 months.

You could do roughly the same procedure in the time table you have, but I think you’d be cutting it very close. Maybe after 7 days, slowly raise the temp 2 degrees a day. Then the day you leave drop it down to lagering temp.

I think 2 weeks to ferment and do the D rest is cutting it pretty thin. I start my lagers at ~48° and let them go at that temperature for about 10 days then I bring them up to the mid 60s and leave them there for 2 or 3 more weeks. I don’t check the gravity anymore before bringing the temperature up, just around the 3-4 week mark before I lager.

You could brew it and bring it up before you leave. Just do an extended D-Rest while you’re gone. It’s not really hurting anything (I don’t think) to leave it sit at that temp for a few weeks before lagering when you get back. Right? Maybe?

What yeast are you using? I’ve used 34/70 and a few liquid yeasts that don’t need a d-rest.

Another suggestion I’d give would be to just let it sit at 45-50F through the next 2 weeks and duration of your trip. Then when you get home, taste for diacetyl. If it’s good, drop it to 35F and lager for 4-12 weeks.

I don’t do a d-rest for any lager. I primary for 2 weeks. Secondary for 2-4 weeks with a cold crash a few days before kegging. Works good for me.

Thanks for the feedback.

I’m probably going to go with Wyeast 2206, but i suppose i would be open to others if it would help things out. Ive heard 2206 needs the rest.

http://www.brew-wineforum.com/viewtopic ... 08&t=59851

That link was pretty awesome. I think that a lot of what he said I was already planning to do, but it’s always good to read a thread that starts by saying “This is what I want to talk about, and this is exactly why I am qualified to talk about it”. And some really good discussions to follow the primary post. Thanks for sharing that.

Not sure I entirely agree with the point on skipping the Diacetyl rest. For one, there is no discussion about yeast strain so the process may not apply to all lager types, but also the Diacetyl Rest is not always just to reduce diacetyl. Incorporating a late temperature increase in a lager will also help clean up some of the other byproducts a yeast may create. Whether it’s “necessary” or not is a bit subjective since there’s usually no harm in doing so, and any effect could be minor. Probably need to do some side by side comparison of a split batch, with and without a rest.

But I’m glad I got another view on lager timing. If I can muster a weekday brew sesh I’ll probably be in the17- 18 day range and have plenty of time for the primary fermentation. I would guess that the longer fermentation times are typically due to either under pitching, insufficient oxygenation, differences in starter and wort pitching temps, or anything else that could cause a potential lag. I’ll try to pitch the yeast at a slightly lower temp than the wort, since the increase in temp will give the yeast a bit of a jump start.

17-18 days is plenty of time to ferment, raise the temp, d-rest, then drop down to lagering temp before you leave.

Good luck :cheers:

You could brew a lower gravity lager, which should reach the FG in time. Somewhere in the 1.039 - 1.045 range.

chaglund, good observations.

Brian has a lot of experience. But if it is only with 1 or 2 yeast strains, YMMV.

I read something about a “quick test” for diacetyl. Something about taking a sample and spitting it in 2. Warm 1 sample and taste them both. I might be wrong. An internet search should clear it up.

[quote=“Nighthawk”]chaglund, good observations.

Brian has a lot of experience. But if it is only with 1 or 2 yeast strains, YMMV.

I read something about a “quick test” for diacetyl. Something about taking a sample and spitting it in 2. Warm 1 sample and taste them both. I might be wrong. An internet search should clear it up.[/quote]