WHEN to D-rest!? Help

[ScottMathsonPro]

I have a Maibock Lager in the fermenter right now. Yeast (Safale W 34/70) was pitched on the warmer side on May 24th. Fermentation and blow off action took off well within the first 24 hours. I got the temps down and as of today, the 28th, it is sitting at 54 degrees Fahrenheit.
This is my first lager and I have been reading about a much needed "d rest".
But when!? How will I be able to tell when it's about the last two days of fermentation to do the rest?
As of right now, it bubbles in the fermentation lock every 7-9 seconds or so.
In advance, thank you for your help and responses!

 

[phoenixs4r]

When you've reached 75% of your targeted FG I believe.

 

[OhCrap]

What was you're OG? When you get to 75% done then d-rest...that's what i was told on here by those who know !!!!
So you get your OG & expected FG and work out what 75% is, then you rest it before racking & lagering

If I'm wrong I will be corrected by more experienced brewers

 

[g-star]

Fermenting warm for the first 4 days defeats the purpose of using lager yeast. That's when all the growth/ester development occurs. You're also likely to develop excess diacetyl this way.

If you pitch cold (44F) with the correct amount of yeast you won't have to worry about this stuff.

In this situation, warm it up when the batch has reached 75-80% attenuation. This may help clean up at least some of the off flavors.

If you need a blow-off tube for a lager, you're fermenting much too warm. A Maibock should start at 44F and slowly rise to 50F, going slow and steady for about two weeks. No need to go above 50F if you pitch the right amount of yeast.

 

[jeepinjeepin]

Fermenting warm for the first 24-36hrs defeats the purpose of using lager yeast. That's when all the growth/ester development occurs. You're also likely to develop excess diacetyl this way.

If you pitch cold (44F) with the correct amount of yeast you won't have to worry about this stuff.

In this situation, warm it up when the batch has reached 75-80% attenuation. This may help clean up at least some of the off flavors.

Exactly. Pitch a proper amount of healthy yeast. Start cool and warm slowly(extreme generalization). Shouldn't need any sort of d-rest. Just a standard lagering time.

 

[ScottMathsonPro]

Here's where I'm stuck: I didn't take on Og.....very stupidly may I add.
So yeah....

 

[jeepinjeepin]

Here's where I'm stuck: I didn't take on Og.....very stupidly may I add.
So yeah....

Do you know what the recipe was supposed to be?

 

[looneybomber]

The d rest seems some what allusive. Why do it? Can't you just let the wort sit in the primary for a while after it's done fermenting at the normal fermentation temps and call it good?

 

[sirsloop]

Ya... Guess the OG.

 

[phoenixs4r]

You're also likely to develop excess diacetyl this way.

? I thought diacetyl was produced due to cold conditions, which is why folks do a d-rest and warm the beer up. Off flavors from too warm a fermentation yes, diacetyl no.

 

[dale1038]

As soon as you see the krausen even begin to drop, warm it up to basement temps. Or room temp if you have no basement. Leave it on the yeast cake 3 weeks. Rack.

 

[g-star]

? I thought diacetyl was produced due to cold conditions, which is why folks do a d-rest and warm the beer up. Off flavors from too warm a fermentation yes, diacetyl no.

Well, I can only speak from my experience. I never do any kind of diacetyl rest, and I pitch cold (43-44F). I then let it rise over 36hrs to 48-50F and hold it there. After 2-3 weeks, depending on OG, I rack to a keg and begin lagering.

The key is to pitch the correct amount of yeast...which is A LOT. I have never had any diacetyl problems this way. The one time I did, I pitched warm (60F), and then tried to cool it down once it kicked off, after about 24hrs. By then it was too late and I had the dreaded buttery O-fest.

People warm up their lagers for a d-rest to encourage the yeast to clean up the off flavors they created in the first place by pitching warm and/or not enough yeast.

 

[Yooper]

People warm up their lagers for a d-rest to encourage the yeast to clean up the off flavors they created in the first place by pitching warm and/or not enough yeast.

Not necessarily! Although pitching cold is my preference, that's not because of diacetyl. It's because of ester production and other off flavors.

Some yeast strains are notorious for producing diacetyl, even if pitched appropriately and fermented at the correct temperatures.

Sometimes a diacetyl rest may not be needed, but it never hurts to do one.

Pitching a lager too warm and keeping it there for several days isn't really going to create much more diacetyl, as much as esters and other byproducts of fermentation.

 

[ScottMathsonPro]

Alright so I did find info on my recipe and OG should be anywhere between 1.072-1.076
FG anywhere between 1.016-1.020
I'll try to figure out the 75% point and take a reading.

 

[ScottMathsonPro]

Well, I can only speak from my experience. I never do any kind of diacetyl rest, and I pitch cold (43-44F). I then let it rise over 36hrs to 48-50F and hold it there. After 2-3 weeks, depending on OG, I rack to a keg and begin lagering.

The key is to pitch the correct amount of yeast...which is A LOT. I have never had any diacetyl problems this way. The one time I did, I pitched warm (60F), and then tried to cool it down once it kicked off, after about 24hrs. By then it was too late and I had the dreaded buttery O-fest.

People warm up their lagers for a d-rest to encourage the yeast to clean up the off flavors they created in the first place by pitching warm and/or not enough yeast.

Interesting and this definitely sounds like a problem I may run into, as I did pitch it on the warm side, then cooled temps. I appreciate your input and expertise.

 

[jeepinjeepin]

For what it's worth, a ahile back I asked the brewmaster of Red Oak, a local reinheitsgebot Bavarian lager brewery, if he did a diacetyl rest. It almost seemed an insult to him. He said that it is not needed after a proper fermentation. I can't remember his exact explanation. I know he pitches cold.

 

[OhCrap]

For what it's worth, a ahile back I asked the brewmaster of Red Oak, a local reinheitsgebot Bavarian lager brewery, if he did a diacetyl rest. It almost seemed an insult to him. He said that it is not needed after a proper fermentation. I can't remember his exact explanation. I know he pitches cold.

From the information I've found here (yooper etc) if it's a cold pitch and a proper temp controled long cool fermentation then d-rest may not be necessary BUT it wouldn't hurt to do one anyway.... I stand to be corrected but that's my reading of the info on here

 

[jeepinjeepin]

From the information I've found here (yooper etc) if it's a cold pitch and a proper temp controled long cool fermentation then d-rest may not be necessary BUT it wouldn't hurt to do one anyway.... I stand to be corrected but that's my reading of the info on here

Correct. One may not be needed but it also won't hurt anything either. Better safe than sorry before lagering.

 

[Denny]

Take a gravity reading. Taste the sample. If you taste diacetyl, do the rest. If you don't, skip it.

 

[Denny]

From the information I've found here (yooper etc) if it's a cold pitch and a proper temp controled long cool fermentation then d-rest may not be necessary BUT it wouldn't hurt to do one anyway.... I stand to be corrected but that's my reading of the info on here

Why would you dio it if it isn't necessary?

 

[OhCrap]

Why would you dio it if it isn't necessary?

As I said I stand corrected BUT it wouldn't hurt, better to be safe than sorry. Wouldn't you prefer to do a drest for 2/3 days before lagering than to find out in 6/7 weeks that you should have done it?

 

[Denny]

As I said I stand corrected BUT it wouldn't hurt, better to be safe than sorry

If you don't taste diacetyl in the beer, you simply do not need to do a d rest. "Better safe than siorry" is a good theory if you have a question about it, but if there's no diacetyl, why bother?

 

[OhCrap]

If you don't taste diacetyl in the beer, you simply do not need to do a d rest. "Better safe than siorry" is a good theory if you have a question about it, but if there's no diacetyl, why bother?

I agree but does it not get more pronounced over time? Also for someone who dosent know what diacetyl is then For the sake of raising the temp for a couple of days I'd do it..... Different horses for different courses. Thee are people who will argue that either option is better...

 

[dawgmatic]

If you don't taste diacetyl in the beer, you simply do not need to do a d rest. "Better safe than siorry" is a good theory if you have a question about it, but if there's no diacetyl, why bother?

Here is a response from yooper to a similar thread asking why.

Because some people can't taste diacetyl, and sometimes it's very hard to detect in small amounts. But it gets worse with lagering, so a very mild "slick" mouthfeel might be a butter bomb after lagering!

 

[Denny]

I agree but does it not get more pronounced over time? Also for someone who dosent know what diacetyl is then For the sake of raising the temp for a couple of days I'd do it..... Different horses for different courses. Thee are people who will argue that either option is better...

If it gets more pronounced, it's due to an infection and there's nothing you can do about it. If you don't taste diacetyl near the end of fermentation, when you'd do the rest, there is none due to fermentation issues and a rest isn't necessary. I used to do a d rest as a matter of course, but I stopped when I realized I was wasting time and effort.

 

[OhCrap]

"Better safe than siorry" is a good theory if you have a question about it

Each to their own.....but if it's his first lager and isn't sure what to do then tell when a d-rest should be done (as per his q) and let him decide what to do after that. It's better to see 2 sides of a discussion and make a decision then.

 

[Denny]

Yes, it certainly is. I must have missed that it's his first lager. Sure, what the heck, do the d rest. Like an iodine test, it's good to do it once or twince before you decide you likely never need to do it again.

 

[dale1038]

I actually bring all my beers up to room temp for a week to aid in attenuation. Sometimes its needed, sometimes not. It's a habit now, or I guess laziness because I won't take the 5 minutes to take a gravity reading.

 

[ScottMathsonPro]

I actually bring all my beers up to room temp for a week to aid in attenuation. Sometimes its needed, sometimes not. It's a habit now, or I guess laziness because I won't take the 5 minutes to take a gravity reading.

Hah I hear ya man and I appreciate your input, well here goes nothing. I'm going for the d rest. Even if it is not completely necessary I believe it will help with an off favors I may have incurred by pitching the lager yeast warm.

 

[marcelo]

the diacetyl rest also works for other off flavor? is my light lager with a flavor reminiscent of chlorine. do d rest can help?