Can I add dry yeast to kegged laget to clean up diacytl?

[TimBrewz]

Hi guys, not sure hat happened with my American Lager, it seemed D-free at kegging. I fermented at 52f with Wy2035 for 21 days, warmed 64 for 3 days, racked to keg and lagered for 2 months. Anyway the beer is going on tap at an important event next weekend. I just took sample and it is now a butter bomb? I am warming it up right now and thinking of throwing a packet of dry yeast in the keg. Would the dry yeast be able to gobble up the diacetyl? I know it would cloud the beer a bit, but if it works I can always filter to another keg if needed.

Thanks, Tim

 

[Denny]

I think it would work better with actively fermenting wort. Also, since the d developed later, it might be due to an infection.

 

[BigFloyd]

It sounds like your ferment/d-rest/lagering schedule was solid.

If you haven't filtered the original yeast out of it, there may be enough left to eat the diacetyl. That's a crap shoot. If you re-pitch with some dry, I'd be sure to rehydrate it first due to the alcohol present. Give it 3-4 days and then cold crash it, it may clear up decently.

Good luck with this.

 

[TimBrewz]

Thanks guys. Denny, if its an infection, would I run a greater risk if ruining the beer by warming it up?

 

[Denny]

Thanks guys. Denny, if its an infection, would I run a greater risk if ruining the beer by warming it up?

Yeah, I think so.

I just don't think adding a pack of dry yeast will help. If you're going to krausen, you need a qt. or 2 of actively fermenting wort.

 

[TimBrewz]

OK I am going to try a krausen. I have 3 days...going to get a starter on the stir plate this morning and add it at high krausen.

 

[Denny]

OK I am going to try a krausen. I have 3 days...going to get a starter on the stir plate this morning and add it at high krausen.

I think that's gonna be your best bet. Let us know how it works out.

 

[hunter_le five]

Curious to hear the results. Subscribed.

 

[TimBrewz]

Hey guys, before I try this, what are potential risks? The beer is drinkable, but obviously has the diacetyl issue. I am expecting clarity to decrease, and gravity to change a tiny bit (OG was 1.040, starter is 1.035) as long as I follow proper sanitary practices, is there any risk of this addition of an active starter ruining my beer?

Thanks, Tim

 

[TimBrewz]

Alright, the deed is done. Pitched a very active 2L starter of American Ale yeast into the room temp keg of lager. This was quite an event, and the lager seemed to instantly reject the alien yeast and I had a huge foamy mess billowing out of the keg. I supposed the fact that the lager was already somewhat carbed has to do with this. Anyway, I popped the lid on the keg and let sit overnight. Relieved the pressure this morning, will check the taste of the krausened lager tomorrow. Fingers crossed

 

[Denny]

Hey guys, before I try this, what are potential risks? The beer is drinkable, but obviously has the diacetyl issue. I am expecting clarity to decrease, and gravity to change a tiny bit (OG was 1.040, starter is 1.035) as long as I follow proper sanitary practices, is there any risk of this addition of an active starter ruining my beer?

Thanks, Tim

Based on my experience, I haven't run into any problems doing it.

 

[Denny]

Alright, the deed is done. Pitched a very active 2L starter of American Ale yeast into the room temp keg of lager. This was quite an event, and the lager seemed to instantly reject the alien yeast and I had a huge foamy mess billowing out of the keg. I supposed the fact that the lager was already somewhat carbed has to do with this. Anyway, I popped the lid on the keg and let sit overnight. Relieved the pressure this morning, will check the taste of the krausened lager tomorrow. Fingers crossed

It may take longer than a day to notice results. It may not, but don't freak out if it doesn't seem to be working in a day.

 

[ajdelange]

Hi guys, not sure hat happened with my American Lager, it seemed D-free at kegging. I fermented at 52f with Wy2035 for 21 days, warmed 64 for 3 days, racked to keg and lagered for 2 months. Anyway the beer is going on tap at an important event next weekend. I just took sample and it is now a butter bomb?

I might be able to help you WRT what happened. Diacetyl is formed in the lagering vessel or package by non enzymatic oxidation of alpha-acetolactate. The traditional way to prevent this is to make sure yeast go in with the ruh beer and that there is enough residual sugar to keep the yeast alive so that they can reabsorb the diacetyl formed and reduce in to less strongly flavored compounds (acetoin and 2,3 butane diol). The 'modern' way to do it is to raise the temperature at the end of the fermentation so that all the acetolactate converts quickly and the yeast suck up the resulting diacetyl.

There is a simple test to see if you are transferring potential diacetyl to your lagering vessel. Warm some of the beer. If you smell that butter smell, it does and you must either do a diacetly rest or make sure plenty of yeast goo into the lagering tank with the beer.

I am warming it up right now and thinking of throwing a packet of dry yeast in the keg. Would the dry yeast be able to gobble up the diacetyl?

Yes, probably provided there is some residual sugar left to let the yeast metabolism come up to speed. Krausen beer would, as has been pointed out here, be better.

 

[Denny]

Great info, AJ!

 

[IslandLizard]

Great explanation, AJ!

Maybe someone can show some light on this. I know you're saving your lager, and in a very short time. So whatever works is just great.

But, when you pitch the new starter at high krausen, without first crashing and decanting it, you're adding 2 liters of pretty bad tasting starter beer to 21 liters of your good beer. That's 10%. Won't that show up as an off-flavor?

 

[TimBrewz]

Great explanation, AJ!

Maybe someone can show some light on this. I know you're saving your lager, and in a very short time. So whatever works is just great.

But, when you pitch the new starter at high krausen, without first crashing and decanting it, you're adding 2 liters of pretty bad tasting starter beer to 21 liters of your good beer. That's 10%. Won't that show up as an off-flavor?

Yes, the off flavors have crossed my mind. I guess I am potentially trading one off flavor for another. However, I think the strong diacetyl flavor is potentially more off-putting than the 10% of unhopped starter. I am just glad I have 2 other kegs of great beer for the event this weekend (an annual fishing trip with all the Dads and Gramdads in my family). Worst case, I stop and buy a couple cases of Coors Light for them

 

[Denny]

Great explanation, AJ!

Maybe someone can show some light on this. I know you're saving your lager, and in a very short time. So whatever works is just great.

But, when you pitch the new starter at high krausen, without first crashing and decanting it, you're adding 2 liters of pretty bad tasting starter beer to 21 liters of your good beer. That's 10%. Won't that show up as an off-flavor?

Unfortunately, doing that pretty much negates what you're trying to accomplish. You need to use actively fermenting wort since there's nothing left in the beer you're adding to that would ferment. despite the fact that I always advocate crashing and decanting in normal situations, I haven't found a negative flavor impact the few times I've krausened a beer.

 

[IslandLizard]

Unfortunately, doing that pretty much negates what you're trying to accomplish. You need to use actively fermenting wort since there's nothing left in the beer you're adding to that would ferment. despite the fact that I always advocate crashing and decanting in normal situations, I haven't found a negative flavor impact the few times I've krausened a beer.

Yeah, the new yeast needs to be very active to clean up the mess the previous group left behind. Maybe some of the off-flavors from the starter beer are cleaned up as well?

Thanks for the peace of mind.
I've tasted starter beer and wondered why it tastes so bad. It's just a medium gravity wort that gets fermented, alas not conditioned. Perhaps it is from the higher temps, oxidation products and overpitching.

 

[limulus]

Regardless of the outcome, I'm interested in hearing how this turns out. Thanks to all for all the good info on this problem.

 

[Hopper5000]

well i hope it works out for this guy. i am curious too because wouldn't adding fresh yeast result in the need to re-lager the beer? I know he added the ale yeast so maybe it's a bit different of a situation because of that?

 

[TimBrewz]

I don't often start the morning with a beer. This morning I took one for the team and pulled 1/2 pint off the warm, krausened lager. I chilled the beer for about 15 minutes in the freezer and sampled it:

Aroma: less butter, more classic clean lager aroma
Taste: Way less diacetyl! Not totally gone, but this surely working! Not as crisp of a lager right now, but maybe it will come back.
Appearance: Cloudy like I expected, I will just deal with the haze, it should drop out mostly after chilling.

I am pretty excited that with your help the beer seems saved!

Recap on procedure:
1. warmed up keg of diacetyl heavy American Lager to mid 60s (basement) let gas off every few hours for a day.

2.Made 2 l starter at 1.035 with pilsen light DME and rehydrated S-05 packet. Place on stir plate and it was volcanic within 3 hours.

3. Added entire starter to keg. Quickly sealed keg, as massive foamy reaction as I added the krausen.

4. Waited 2 days, took sample- Progress!

5. Will chill tonight and recarb in the morning.

By the way, I used the American Ale yeast because I had it, its very neutral and can handle a wide range of conditions. I did not want a super flocculant yeast, the idea is to keep it active as possible. Anyway, a lot of effort but I learned a lot. Thanks, for all the replies. I will report back after the trip.

Cheers, Tim

 

[Denny]

well i hope it works out for this guy. i am curious too because wouldn't adding fresh yeast result in the need to re-lager the beer? I know he added the ale yeast so maybe it's a bit different of a situation because of that?

It might result in that. But it doesn't seem like a big deal.

 

[Denny]

well i hope it works out for this guy. i am curious too because wouldn't adding fresh yeast result in the need to re-lager the beer? I know he added the ale yeast so maybe it's a bit different of a situation because of that?

I don't often start the morning with a beer. This morning I took one for the team and pulled 1/2 pint off the warm, krausened lager. I chilled the beer for about 15 minutes in the freezer and sampled it:

Aroma: less butter, more classic clean lager aroma
Taste: Way less diacetyl! Not totally gone, but this surely working! Not as crisp of a lager right now, but maybe it will come back.
Appearance: Cloudy like I expected, I will just deal with the haze, it should drop out mostly after chilling.

I am pretty excited that with your help the beer seems saved!

Recap on procedure:
1. warmed up keg of diacetyl heavy American Lager to mid 60s (basement) let gas off every few hours for a day.

2.Made 2 l starter at 1.035 with pilsen light DME and rehydrated S-05 packet. Place on stir plate and it was volcanic within 3 hours.

3. Added entire starter to keg. Quickly sealed keg, as massive foamy reaction as I added the krausen.

4. Waited 2 days, took sample- Progress!

5. Will chill tonight and recarb in the morning.

By the way, I used the American Ale yeast because I had it, its very neutral and can handle a wide range of conditions. I did not want a super flocculant yeast, the idea is to keep it active as possible. Anyway, a lot of effort but I learned a lot. Thanks, for all the replies. I will report back after the trip.

Cheers, Tim

Good on ya! Congrats!

 

[Hopper5000]

ya glad it worked out!

 

[TimBrewz]

The beer was very good! It was gone in a day Not a trace of diacetyl. Even cleared to a decently clear level...thanks again for the support. I feel like I have another tool in my brewing toolbox.

 

[Denny]

The beer was very good! It was gone in a day Not a trace of diacetyl. Even cleared to a decently clear level...thanks again for the support. I feel like I have another tool in my brewing toolbox.

Too cool! Krausening is a technique that too few people are aware of. Glad to hear it worked for you.

 

[TheJasonT]

I'm curious about something you mentioned here - you said you did a 21 day primary ferment before D-Rest and lagering. Is that a normal length of time for lagers in general or just for you? Is it possible that such a long cool fermentation caused the yeast drop out and "forget" to clean up the diacetyl? What I've been reading about lagers is that you want to bump up the temp to a D-rest when you're at about 90% of the expected FG.

Currently I only do ales but I'm looking forward to trying my hand at lagers now that I have a temp controlled area to do so. Therefore my knowledge is only "book smarts".

-Jason

 

[SpeedYellow]

Glad it worked! I recently had the same prob - kegged a lager only to find a d-bomb. Undrinkable and getting worse. My solution was simple- pulled the keg from the fridge and laid it on its side (to maximize the yeast's contact with the beer) in a bathtub in a warm room, and swirled it up every few days. After 2-3 weeks it was gone, and it turned into a great beer. The yeast that got transferred over while kegging was enough; didn't need to add more.

 

[TimBrewz]

Hey Jason, I guess that is a possibility. I have always given lagers about 2x as long in primary as my ales. This may not be necessary, as many seem done within 10-14 days. I did keep the beer in my temperature controlled fridge which as a margin or error or +/- 2 degrees, I set to 52f, towards the low end of the optimal range for American Lager yeast (50-58f is optimal). So, maybe it was closer to 50f and diacetyl is produced more with colder fermentations. So maybe the yeast dropped out too much for the D-rest to work. Next time I will rouse the yeast a bit before starting the D-rest and/or warm it up when there is still a bit of activity in the fermenter. Anyway, adding the krausen was amazing.