Persistent Diacetyl in Lager

Jeff,

Thanks for the pointer to braukaiser.com. I read the chapter on Fermenting Lagers and it was an very interesting read.

I found the discussion on the six different fermentation schedules to be of interest. My personal lager fermentation schedule doesn’t match any of the six presented but I did enjoy the discussion of the compare/contrast of these six representative schedules. I also thought it was interesting that the conventional schedule doesn’t have a diacetyl rest. This is consistent with my previous post of: “Some European Commercial Breweries actually don't do Diacetyl rests on their lagers - learned this fact from Chris White of White Labs during his talk at ANHC. The breweries that don't do them simply have a very long lagering period instead.”

There was also a section on Adding Kraeusen which would probably be of great interest to Peter. Within this section there is discussion on how to ‘harvest’ the primary lager yeast (2035 for Peter) to make a starter for krausening:

“One way of getting some yeast out of the primary is to use a sanitized racking cane. Use your thumb to keep one end closed and push it into the carboy. Then release the thumb and beer will rush into the cane and pull a lot of yeast with it. Close the cane off again, pull it out and dump its contents in the starter vessel. This should be repeated 5-10 times to get enough yeast into the starter. Now the yeast in the starter is allowed to start fermentation at primary fermentation temperatures. When the beer is then racked to the secondary, the Kraeusen is added without adding the layer of yeast sediment that may have already settled on the bottom.”

Do you think it would be ‘better’ for Peter to use a 2035 starter for his Krausen vs. a starter made from Nottingham?

Anyhow, thanks for the continuing beer education. I really enjoyed it!

Cheers!

Jack

 

“I've tried adding krausen to help fix it after the fact but never had great success with that method.” So, I take it that the diacetyl was not reduced during your lagering phase? What are the details of your lagering phase: temperature and duration? The reason I ask is because I still think it is possible for diacetyl to be reduced during the lagering phase but it seems that this is highly dependent on yeast strain and length of the lager phase (and maybe lager temperature?).

Cheers!

 

Yeah, I think I didn't add enough karausen when I tried that method. I still had diacetyl afterwards.

I've tried extended lagering, for low levels of diacetyl it seems to help, but for higher levels I haven't seen it work. I pretty much have my process down and haven't had any diacetyl issues in almost 2 years now. I feel I've gotten it under control using the appropriate d-rest method.
I only brew lagers twice a year, but do multiple batches each time. I've tried many of Wyeasts Lagers, but lately I've been sticking to their Octoberfest Blend. I've gotten used to that strain and like it's characteristics. The shortest I'll lager for is 4 weeks at 32-33 and serve at that temp as well. But I often leave lagers at that temp for many months. I have a bock and a dopplebock approaching the 4 month mark.

If you find a lagering method that works for reducing diacetyl on a homebrew level I would love to hear about. Diacetyl can be a tricky one to figure out. I'm sure it can be done, just difficult to do. Those lager yeasties can be overly sensitive at times. What we need is a more robust lager yeast strain.

Cheers,

 

“If you find a lagering method that works for reducing diacetyl on a homebrew level I would love to hear about. Diacetyl can be a tricky one to figure out. I'm sure it can be done, just difficult to do. Those lager yeasties can be overly sensitive at times. What we need is a more robust lager yeast strain.”

I am not too sure what to say here. I guesstimate that I have brewed 60-70 batches of lager (so far). I have used numerous different types of lager yeasts. I have never conducted a diacetyl rest and I have never got diacetyl in any of my lagers. I have very sensitive taste buds for diacetyl so if it was there I would know it. I can only guess that my lagering schedule is ‘friendly’ to all types of lager yeast since I have never had a diacetyl issue?

Cheers!

 

WLP-833 is low on Diacetyl production. The Mexican Lager yeast. WLP-940 is said to be very clean and a low Diacetyl producer.

 

WLP833 is my go-to lager strain for a number of reasons, but I suppose low diacetyl would be one of them.

I personally tend to follow the "F-schedule" as shown in Brau Kaiser's excellent information. Pitched cold, fermented a 2-3 degrees warmer and then once most of the krausen has fallen I raise the temp (gradually, in stepped fashion, or with a natural rise - doesn't seem to make a difference) to 65-68 degrees. I don't even taste for diacetyl at this time because I'm doing the temp raise for more than just protection against the compound; I've found it's great for finishing out the beer and I honestly feel that the yeast clean up a lot more in this maturation rest. I definitely think that I don't need to lager most of my 6% or less beers for more than 4-5 weeks while doing this schedule (and using WLP833).

Good luck to you.