[Bel Air Brewing]

I have previously had good results removing diacetyl from beer in a keg by pitching some harvested yeast. In a week's time, the beer cleaned up.

But I have no yeast slurry now, only fresh dry yeast (Diamond, S-189).

Would pitching this straight into the keg do the trick? Or, is a starter required?

[denny]

I have previously had good results removing diacetyl from beer in a keg by pitching some harvested yeast. In a week's time, the beer cleaned up.

But I have no yeast slurry now, only fresh dry yeast (Diamond, S-189).

Would pitching this straight into the keg do the trick? Or, is a starter required?

It will work better if it's active, in my experience.  I'd advise making a small starter.

[dmtaylor]

If refrigerated, I would simply recommend warming up the beer for 3 weeks.  I always hear claims that a diacetyl rest of ~3 days is adequate; however, this has not been my experience at all for dozens of batches.  Instead, I find that the diacetyl is usually gone after about 2-4 weeks, average being 3 weeks.

I don't get diacetyl with every batch of lager, but when I do, that's how I handle it.  No additional yeast pitch required.  Krausening with fresh yeast might accelerate this, but... I'm a patient man.

[Bel Air Brewing]

I have previously let the keg sit at room temp for a week or so, with no change or improvement.

The diacetyl was not noticed at kegging time, but it is detectable now. And a D-Rest was performed in the fermenter, for about 4 or 5 days.

This is a Festbier, so it needs to be addressed.

Thanks for the input!

[dmtaylor]

I have previously let the keg sit at room temp for a week or so, with no change or improvement.

Like I say, I am not surprised.  "a week or so" is not enough time, in my experience.  Try about 3 weeks.

[Village Taphouse]

For the record I have a beer on tap right now that had a touch of diacetyl.  I moved the keg upstairs and put it into a warm closet for about 1 week.  The moving of the keg roused the yeast and every 1-2 days I would just pull the release pin a bit.  After a week I connected a cobra tap and the diacetyl was gone and the beer was a bit flatter than it should be.  I put it back into the draft fridge and checked it daily and after 3-4 days it was carbed properly again.  This is my standard "remove the D" process and I supposed YMMV.  It has never taken me 3 weeks but I suppose it depends on the conditions, variables, amount of diacetyl, etc.  I have never had to repitch yeast to remove it. 

[tommymorris]

For the record I have a beer on tap right now that had a touch of diacetyl.  I moved the keg upstairs and put it into a warm closet for about 1 week.  The moving of the keg roused the yeast and every 1-2 days I would just pull the release pin a bit.  After a week I connected a cobra tap and the diacetyl was gone and the beer was a bit flatter than it should be.  I put it back into the draft fridge and checked it daily and after 3-4 days it was carbed properly again.  This is my standard "remove the D" process and I supposed YMMV.  It has never taken me 3 weeks but I suppose it depends on the conditions, variables, amount of diacetyl, etc.  I have never had to repitch yeast to remove it.

This is what I do. I just check the warm beer every few days until it is clean. I think there are times when krausening is necessary.  I think that’s probably where Bel Air is right now.

[Bel Air Brewing]

For the record I have a beer on tap right now that had a touch of diacetyl.  I moved the keg upstairs and put it into a warm closet for about 1 week.  The moving of the keg roused the yeast and every 1-2 days I would just pull the release pin a bit.  After a week I connected a cobra tap and the diacetyl was gone and the beer was a bit flatter than it should be.  I put it back into the draft fridge and checked it daily and after 3-4 days it was carbed properly again.  This is my standard "remove the D" process and I supposed YMMV.  It has never taken me 3 weeks but I suppose it depends on the conditions, variables, amount of diacetyl, etc.  I have never had to repitch yeast to remove it.

This is what I do. I just check the warm beer every few days until it is clean. I think there are times when krausening is necessary.  I think that’s probably where Bel Air is right now.

That's what we are thinking. Going to do another taste test today with a friend, to determine the best approach.
Need to clean this beer up soon as I would like to take the keg to a Christmas Party.

[HighVoltageMan!]

I brew a lot of lagers and rarely get any VDK/diacetyl, but I do perform a D-rest. The D-rest shouldn't take more than a couple of days, but I'm sure it could vary from strain to strain. If you keep having a VDK problem, adding yeast after the fact is a band-aid approach, there is something wrong in your process. Aeration rates, pitch rates, yeast health and yeast strains all have an impact on VDK production.

I don't like diacetyl in my beer either, the problem I have is that I'm not that sensitive to it. So when I send it off to a competition I'm not 100% sure I got rid of it. So now I add ALDC at pitch to eliminate any butter aroma/flavor. I never really had much of a problem, but the ALDC adds some level of assurance that I don't have it in my beer. More Beer carries it. I can get @ 20-25 batches per bottle, which is about a years worth for me. It's a little pricey, but if it saves one beer or gets me one more medal, it's worth it.

https://www.morebeer.com/products/cellarscience-aldc-enzyme.html

It's targeted toward Hazy IPA's to reduce VDK from hop creep, but many lager brewers, both pro and amateurs alike, are adding this at pitch.

EDIT: I believe it can be added post fermentation too, it just has to be mix into the beer well.

[tommymorris]

I brew a lot of lagers and rarely get any VDK/diacetyl, but I do perform a D-rest. The D-rest shouldn't take more than a couple of days, but I'm sure it could vary from strain to strain. If you keep having a VDK problem, adding yeast after the fact is a band-aid approach, there is something wrong in your process. Aeration rates, pitch rates, yeast health and yeast strains all have an impact on VDK production.

I don't like diacetyl in my beer either, the problem I have is that I'm not that sensitive to it. So when I send it off to a competition I'm not 100% sure I got rid of it. So now I add ALDC at pitch to eliminate any butter aroma/flavor. I never really had much of a problem, but the ALDC adds some level of assurance that I don't have it in my beer. More Beer carries it. I can get @ 20-25 batches per bottle, which is about a years worth for me. It's a little pricey, but if it saves one beer or gets me one more medal, it's worth it.

https://www.morebeer.com/products/cellarscience-aldc-enzyme.html

It's targeted toward Hazy IPA's to reduce VDK from hop creep, but many lager brewers, both pro and amateurs alike, are adding this at pitch.

EDIT: I believe it can be added post fermentation too, it just has to be mix into the beer well.

That’s an interesting product.

[Bel Air Brewing]

Yes, I agree it's a band aid approach. My brewing process is pretty meticulous, with an emphasis on sanitation. Not saying my process is perfect.

A D-Rest is always employed.

Just won a Gold at the Dixie Cup for my Irish Red. One out of three judges commented on diacetyl. The other two never mentioned it, or any off flavors.

[Village Taphouse]

I brew a lot of lagers and rarely get any VDK/diacetyl, but I do perform a D-rest. The D-rest shouldn't take more than a couple of days, but I'm sure it could vary from strain to strain. If you keep having a VDK problem, adding yeast after the fact is a band-aid approach, there is something wrong in your process. Aeration rates, pitch rates, yeast health and yeast strains all have an impact on VDK production.

I don't like diacetyl in my beer either, the problem I have is that I'm not that sensitive to it. So when I send it off to a competition I'm not 100% sure I got rid of it. So now I add ALDC at pitch to eliminate any butter aroma/flavor. I never really had much of a problem, but the ALDC adds some level of assurance that I don't have it in my beer. More Beer carries it. I can get @ 20-25 batches per bottle, which is about a years worth for me. It's a little pricey, but if it saves one beer or gets me one more medal, it's worth it.

https://www.morebeer.com/products/cellarscience-aldc-enzyme.html

It's targeted toward Hazy IPA's to reduce VDK from hop creep, but many lager brewers, both pro and amateurs alike, are adding this at pitch.

EDIT: I believe it can be added post fermentation too, it just has to be mix into the beer well.

I will let lagers sit in a fridge for 4-5 days and eventually bring the fermenter out of the fridge where it rests at room temp.  When the weather is warmer, everything works as it should.  When it gets cooler, that time sitting at room temp is (sometimes) not warm enough to remove the diacetyl.  So I have a system in place to deal with it but the system needs an adjustment based on season.  What is the magic temp to remove diacetyl?  Is there one?

[HighVoltageMan!]

I brew a lot of lagers and rarely get any VDK/diacetyl, but I do perform a D-rest. The D-rest shouldn't take more than a couple of days, but I'm sure it could vary from strain to strain. If you keep having a VDK problem, adding yeast after the fact is a band-aid approach, there is something wrong in your process. Aeration rates, pitch rates, yeast health and yeast strains all have an impact on VDK production.

I don't like diacetyl in my beer either, the problem I have is that I'm not that sensitive to it. So when I send it off to a competition I'm not 100% sure I got rid of it. So now I add ALDC at pitch to eliminate any butter aroma/flavor. I never really had much of a problem, but the ALDC adds some level of assurance that I don't have it in my beer. More Beer carries it. I can get @ 20-25 batches per bottle, which is about a years worth for me. It's a little pricey, but if it saves one beer or gets me one more medal, it's worth it.

https://www.morebeer.com/products/cellarscience-aldc-enzyme.html

It's targeted toward Hazy IPA's to reduce VDK from hop creep, but many lager brewers, both pro and amateurs alike, are adding this at pitch.

EDIT: I believe it can be added post fermentation too, it just has to be mix into the beer well.

I will let lagers sit in a fridge for 4-5 days and eventually bring the fermenter out of the fridge where it rests at room temp.  When the weather is warmer, everything works as it should.  When it gets cooler, that time sitting at room temp is (sometimes) not warm enough to remove the diacetyl.  So I have a system in place to deal with it but the system needs an adjustment based on season.  What is the magic temp to remove diacetyl?  Is there one?

There isn't a magic temperature for a d-rest. It requires the yeast to be active and in suspension. The warmer temperatures increase the metabolic rate of yeast and that causes the the diacetyl to clean up quicker. Healthy yeast can do this in their normal temperature range, but it requires them to be active. Flocculated yeast is unlikely to have much of an effect on diacetyl/VDK levels. It's best to perform a d-rest during active fermentation just prior to reaching final gravity. For ales there really isn't much to do, for lagers raising the temp 10-15F can speed things up.

[denny]

I brew a lot of lagers and rarely get any VDK/diacetyl, but I do perform a D-rest. The D-rest shouldn't take more than a couple of days, but I'm sure it could vary from strain to strain. If you keep having a VDK problem, adding yeast after the fact is a band-aid approach, there is something wrong in your process. Aeration rates, pitch rates, yeast health and yeast strains all have an impact on VDK production.

I don't like diacetyl in my beer either, the problem I have is that I'm not that sensitive to it. So when I send it off to a competition I'm not 100% sure I got rid of it. So now I add ALDC at pitch to eliminate any butter aroma/flavor. I never really had much of a problem, but the ALDC adds some level of assurance that I don't have it in my beer. More Beer carries it. I can get @ 20-25 batches per bottle, which is about a years worth for me. It's a little pricey, but if it saves one beer or gets me one more medal, it's worth it.

https://www.morebeer.com/products/cellarscience-aldc-enzyme.html

It's targeted toward Hazy IPA's to reduce VDK from hop creep, but many lager brewers, both pro and amateurs alike, are adding this at pitch.

EDIT: I believe it can be added post fermentation too, it just has to be mix into the beer well.

I will let lagers sit in a fridge for 4-5 days and eventually bring the fermenter out of the fridge where it rests at room temp.  When the weather is warmer, everything works as it should.  When it gets cooler, that time sitting at room temp is (sometimes) not warm enough to remove the diacetyl.  So I have a system in place to deal with it but the system needs an adjustment based on season.  What is the magic temp to remove diacetyl?  Is there one?

Temp doesn't matter. You're just trying to make the yeast more active.  You could even let the lager ferment longer and skip the d rest completely.

[hopfenundmalz]

The traditional lager brewing didn't have a diacetyl rest, just a looonnng time at Lagering temps.

One way to look at it is that it is something like an integral of area under the time temperature curve with Arrhenius factor thrown in.