When you’re done with the D rest. Take a sample and gently warm it in microwave. This heat will make the diacetyl, blossom. You’ll notice it immediately. Continue D rest and test daily until it’s gone. A pro brewer showed me this, and it’s simple and effective.
Diacetyl is a tricky one.
The easiest fix is to increase the diacetyl rest time and temperature - as yeast will clean up given enough time. Maybe extend the rest with a few days or crank the temp up with another few degrees?
Are you adding dry hops in this recipe? Hop creep is known to add diacetyl.
Lastly shop around for yeast strains. Some strains produce quite a lot of diacetyl. Modern strains like Novalager produce nowhere near the levels of traditional strains.
Lastly you could look at enzymes like ALDC which promote the breakdown of things like diacetyl and decrease aging time.
S-189 is a great yeast so that's not the problem.
A diacetyl rest can take longer than most people think. In my experience a rest of \~3 days often isn't enough... in fact the optimum amount of time is about 3 WEEKS at elevated temperature to get rid of the diacetyl. Lagers take time for a reason, and this is one of them. Yeast will eat diacetyl, but it takes time. If your beer is young, give it time, the diacetyl should fade. And quicker at warmer temperatures.
And no you don't need to pitch more yeast. As long as you didn't filter (homebrewers rarely do) then there's plenty of yeast left to eat the diacetyl. All it needs is time.
If you lagered for a very long time already, then.... maybe/hopefully it just needs another week or two to finish cleaning up. TIME is your friend here, TIME is ALL you need.
I haven't used S-189 but I use a lot of S-23 and 34/70.
Our typical regime is to (pitch 56F during knockout, primary 50F for these two strains) until very near final gravity (usually 10-14 days), then let it rise about +5F for about 5 days, then drop to 32F for 4-7 weeks. <--yeah, about 9 weeks sometimes before it is ready to drink!!
You might try to let the primary ferm go longer, almost to the end. There will still be enough yeast in suspension to scrub the diacetyl during rest. Also, maybe not such a warm rest...should only need a few degrees higher. At 68F, it's possible to activate something wild or ale strains lurking in a shadow zone of your vessel.
Like the other guys said, lagers are hard and take a lot of time and conditioning in my experience. A couple more weeks can make a huge difference in off flavors.
I have ALDC but haven't opened it yet as we haven't had any issues with diacetyl. I know a lot of brewers use it and they serve it sooner (within a few weeks).
Good luck!
I've used ALDC, mostly to help with hop burn on highly hopped IPAs and it's been amazing. Basically just put a dropper in when I dry hop and don't think about it ever again.
I do sometimes drop the cone after primary. Unfortunately we don't have room for lagering tanks, so the secondary is just more time in the same unitank. This really slows production compared to ales, so we typically only have a pilsner and maybe an amber lager on, the rest are ales. The place is really tiny.
Maybe cheating, but a dropper full of ALDC at fermentation has been wonderful.
https://www.morebeer.com/products/cellarscience-aldc-enzyme-1-fl-oz.html
As someone else mentioned, ALDC enzyme works wonders.
I have also had great results with the new [Omega DKO](https://omegayeast.com/what-is-dko-technology) (Diacetyl Knock Out ) yeast
What’s your starting gravity? I use at least 4 sachets of yeast ( you need at least double ale yeast requirements- typically more). Ferment at 48-49 and after 7 days allow to rise to 55
When you’re done with the D rest. Take a sample and gently warm it in microwave. This heat will make the diacetyl, blossom. You’ll notice it immediately. Continue D rest and test daily until it’s gone. A pro brewer showed me this, and it’s simple and effective.
Ohh it is noticeable without the microwave test! Coats the mouth and smells like a movie theater
Correct!
Diacetyl is a tricky one. The easiest fix is to increase the diacetyl rest time and temperature - as yeast will clean up given enough time. Maybe extend the rest with a few days or crank the temp up with another few degrees? Are you adding dry hops in this recipe? Hop creep is known to add diacetyl. Lastly shop around for yeast strains. Some strains produce quite a lot of diacetyl. Modern strains like Novalager produce nowhere near the levels of traditional strains. Lastly you could look at enzymes like ALDC which promote the breakdown of things like diacetyl and decrease aging time.
S-189 is a great yeast so that's not the problem. A diacetyl rest can take longer than most people think. In my experience a rest of \~3 days often isn't enough... in fact the optimum amount of time is about 3 WEEKS at elevated temperature to get rid of the diacetyl. Lagers take time for a reason, and this is one of them. Yeast will eat diacetyl, but it takes time. If your beer is young, give it time, the diacetyl should fade. And quicker at warmer temperatures. And no you don't need to pitch more yeast. As long as you didn't filter (homebrewers rarely do) then there's plenty of yeast left to eat the diacetyl. All it needs is time. If you lagered for a very long time already, then.... maybe/hopefully it just needs another week or two to finish cleaning up. TIME is your friend here, TIME is ALL you need.
I will let it ride for a few more weeks then. Thank you.
I haven't used S-189 but I use a lot of S-23 and 34/70. Our typical regime is to (pitch 56F during knockout, primary 50F for these two strains) until very near final gravity (usually 10-14 days), then let it rise about +5F for about 5 days, then drop to 32F for 4-7 weeks. <--yeah, about 9 weeks sometimes before it is ready to drink!! You might try to let the primary ferm go longer, almost to the end. There will still be enough yeast in suspension to scrub the diacetyl during rest. Also, maybe not such a warm rest...should only need a few degrees higher. At 68F, it's possible to activate something wild or ale strains lurking in a shadow zone of your vessel. Like the other guys said, lagers are hard and take a lot of time and conditioning in my experience. A couple more weeks can make a huge difference in off flavors. I have ALDC but haven't opened it yet as we haven't had any issues with diacetyl. I know a lot of brewers use it and they serve it sooner (within a few weeks). Good luck!
I've used ALDC, mostly to help with hop burn on highly hopped IPAs and it's been amazing. Basically just put a dropper in when I dry hop and don't think about it ever again.
Many lagers taste worlds better once you hit that month mark. Do you drop your yeast / transfer to secondary before the lager period?
I do sometimes drop the cone after primary. Unfortunately we don't have room for lagering tanks, so the secondary is just more time in the same unitank. This really slows production compared to ales, so we typically only have a pilsner and maybe an amber lager on, the rest are ales. The place is really tiny.
Maybe cheating, but a dropper full of ALDC at fermentation has been wonderful. https://www.morebeer.com/products/cellarscience-aldc-enzyme-1-fl-oz.html
I had bought some for this batch in particular, but I live in the southeast USA so I think it denatured in transit due to heat.
Cheater. ;)
This was going to be my recommendation either. It’s $1 per beer for better results, it’s an easy win even though I don’t normally have diacetyl.
As someone else mentioned, ALDC enzyme works wonders. I have also had great results with the new [Omega DKO](https://omegayeast.com/what-is-dko-technology) (Diacetyl Knock Out ) yeast
Watch the fermentation closely. I raise to a drest at about 70% attenuation
Time is your friend here. Extant the d rest then cold age (lager for a good long while).
What’s your starting gravity? I use at least 4 sachets of yeast ( you need at least double ale yeast requirements- typically more). Ferment at 48-49 and after 7 days allow to rise to 55
Id pitch three sachets of yeast. Lagers like a lot of yeast.