diacetyl rest details (first lager)

I'm brewing my first lager; a Pilsner Urquell clone. PU has some diacetyl, but I'd rather my clone had as little as possible. I'm not trying for any, in other words.

I made a 3L starter of WLP800 and pitched it at about 62F. Then I put my carboy in my keezmentation chamber at 50F.

I've been told I should monitor my gravity and do a diacetyl rest. My questions are

--at what gravity should I start the diacetyl rest (1.020?)

--what temperature should I do the diacetyl rest at (70F?)

--how long should I do it (just long enough to reach FG, or longer?)

Yes, if you pitched at 60, you'll definitely want to do a diacetyl rest. You normally want to do it when the beer is about 75% of the way to FG, in other words 75% finished. 1.020 or so is a nice round number and that should work, depending on your OG.

68-70 is fine for the diacetyl rest.

You'll want to do the diacetyl rest until there is NO hint of diacetyl in the beer, and it's been at FG for at least a couple of days. Taste the beer when it's finished, and see if you have any slickness in the mouthfeel or any oiliness on the tongue. If you do, continue the d-rest. Some people can't taste diacetyl, so if you're one of them, you could just do a nice long rest to ensure it's gone.

After the diacetyl rest, you can rack and then begin lagering.

/threadjack (sorry)

same question - my first lager, using a 2L starter with 2308 Munich Lager. This is batch #18 for me, but my first lager.

Starter went for 1 day at 70F, and pitched into 65F wort at 1.054 OG. Started fermentation at 65F for 2 days, then brought it down to 50F for 20 days (today). It's barely bubbling, except when I pull the blowoff tube to near the surface of the water.

Gravity today is 1.030, it quite clear and has nothing floating on the top.... Taste is so-so, but smell is light sulphur. I have no idea what diacetal tastes like.

My plan is to now to bring it up to 60F for 2 days for diacetal rest, then rack it and lager at cold temps (not sure what that should be). I have a fridge with temp controller set at 35F now, but can be changed.

Wyeast says "temperature range 48-56F" and a "thorough di-rest is recommended".

1 - what's a thorough diacetal rest? temp? time?
2 - what temp should I lager at?
3 - can I save the yeast the same way I've been saving ale yeasts? ( see sticky thread with glass jars and boiled water)

Thanks!

heckler73 said:

/threadjack (sorry)

same question - my first lager, using a 2L starter with 2308 Munich Lager. This is batch #18 for me, but my first lager.

Starter went for 1 day at 70F, and pitched into 65F wort at 1.054 OG. Started fermentation at 65F for 2 days, then brought it down to 50F for 20 days (today). It's barely bubbling, except when I pull the blowoff tube to near the surface of the water.

Gravity today is 1.030, it quite clear and has nothing floating on the top.... Taste is so-so, but smell is light sulphur. I have no idea what diacetal tastes like.

My plan is to now to bring it up to 60F for 2 days for diacetal rest, then rack it and lager at cold temps (not sure what that should be). I have a fridge with temp controller set at 35F now, but can be changed.

Wyeast says "temperature range 48-56F" and a "thorough di-rest is recommended".

1 - what's a thorough diacetal rest? temp? time?
2 - what temp should I lager at?
3 - can I save the yeast the same way I've been saving ale yeasts? ( see sticky thread with glass jars and boiled water)

Thanks!

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1. It's hard to say how long you need, but fermenting at 65 degrees for a couple of days probably really exacerbated any diacetyl. I'd hold it at diacetyl rest temps until absolutely no hint of diacetyl is in the beer, and then a bit longer. In small amounts, diacetyl isn't so much a taste as a feel- it's got a slight oily feeling. When you take a sample, any slickness on the tongue or teeth means that diacetyl is a problem. If not given enough time to clean up until it's totally gone (or fresh yeast added), it will get worse with lagering.
2. I lager near freezing, at 34 degrees, one week for each 8-10 points of OG. So, for a 1.056 lager, I'd lager for 6-7 weeks as a minimum.
3. Sure, but I probably wouldn't save this one because of the temperature changes and the possibility of stressed (unhealthy) yeast.

I find for the best lagers, a HUGE starter pitched at or slightly below fermentation temperature makes a big difference. I pitch 45 degree yeast (decanted off the spent wort) into a 48 degree wort, and allow the temperature to rise to 50 degrees for fermentation. Fermenting too warm does cause some off flavors that may not go away.

Yooper said:

It's hard to say how long you need, but fermenting at 65 degrees for a couple of days probably really exacerbated any diacetyl.

Click to expand...

^
THIS!!!!!!!!!!!!!!

If your goal is to make the cleanest, best-tasting lager you can make, you MUST pitch cold...like in the mid-40's. Let it naturally rise through the heat of fermentation to about 48-50F and hold it there until its done. Pitching warm exacerbates the most critical off-flavor producing period, the initial yeast growth phase.

If you pitch the correct amount of yeast and aerate/oxygenate properly, fermentation will take off within 12 hours...no worries. And you'll find that a diacetyl rest is more than likely not even necessary (though it won't hurt).

People seemed to get consumed with the minute details of a diacetyl rest, when if they had just started out the right way, it wouldn't even be necessary.

I was just following "your first lager" on the wiki.

https://www.homebrewtalk.com/wiki/index.php/Fermenting_Lagers

Keep this starter at room temperature 68 - 70°F (18 - 19°C) and let it start fermenting.

Once brewed, chill the wort to a temperature below 70°F (20°C). The mid 60's should work best for this fermentation schedule.

Wait until you see fermentation activity (low kraeusen or bubbles in the airlock) until you move the fermenter to an area (basement or fridge) where you have a constant 48 - 52°F (9 - 11°C). Let the primary fermentation take its course for a few (3-4 weeks) until there is no airlock activity left.

After that rack the beer to a lagering vessel. It can be another carboy or a soda keg with shortened dip tube. The beer is then moved to an area where the ambient temperature is between 32°F and 38°F (0 - 3°C), where it will remain for at least another 4 weeks.

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but then...

Among homebrewers there is is often debate regarding the proper pitching temperature for lagers. Some say that you need to pitch warm to allow for better initial growth of the yeast and others say that you need to pitch below the primary fermentation temperature.
To understand that both sides have valid arguments, one has to understand where they are coming from. Warm pitching has been introduced by home brewers and yeast manufacturers because it allows for pitching a lager with a smaller pitching rate and leads to a shorter lag time, which is less concerning for the first-time lager brewer. That's why warm pitching was suggested in the "Your first lager fermentation" section above. To pitch warm, chill your wort until it has a temperature of 65 - 68°F (15 - 18°C), aerate it well and pitch the yeast. Now wait until you see signs of fermentation (low kraeusen or bubbles in the airlock) and move it to an area where you maintain about 50°F so that the wort can cool down while the yeast starts to take off.

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Honestly, my goal isn't to make the cleanest, best tasting lager. I've made 18 batches of ale now, and have never once thought "oh yuck, off flavours....". I'm in no beer competitions and just want to make good drinkable beer for consumption at home.

So, I didn't notice any oily feeling last night, only a bad smell.


Is it normal that after 20 days I'm at 1.030? Should I leave it in the primary until I reach 1.010 and possibly warm it up to 60F to get the yeast working harder for a few days now until it's down to 1.010? Or does the lagering in secondary take it down to FG?

heckler73 said:

Is it normal that after 20 days I'm at 1.030? Should I leave it in the primary until I reach 1.010 and possibly warm it up to 60F to get the yeast working harder for a few days now until it's down to 1.010? Or does the lagering in secondary take it down to FG?

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No, its not normal. You didn't state your OG, but if its an Urquell clone, I would guess somewhere in the neighborhood of 1.050. This type of beer should be near terminal gravity in 7 - 10 days at most.

Your fermentation is slow and/or stuck becuase you in all likelihood didn't pitch enough yeast, then put the brakes on what active yeast was present by chilling it down 15 degrees or so.

There is no gravity movement during lagering. Your best bet now is to rouse the yeast and warm it up into the mid 60's to see if it gets moving again. If not, re-pitching an actively fermenting starter might kick things off again.

OG was 1.054.

It's still bubbling, but we all know that's not a sign of fermentation.

I'll warm it up to 65F and see what happens to the gravity. Today is was 1.028

In parallel, I'm going to make a batch of the same recipe with a German Ale and learn the differences between Ale and Lager.

Thanks!

How did this turn out?

Awesome. I brewed a follow-up with a bit more hops because I felt the first was just a bit too sweet. The second is just a bit too bitter. Both turned out clean-tasting and with no diacetyl.

I don't have my notes but I think I fermented at 10C until the gravity was south of .020, then warmed up to 20C for a week or so, then transferred to a clean fermenter and lagered for as many months as I could stand at normal serving temperature.