Lager still has diacetyl.

[Beeragent]

After several years of successfully brewing ales, I've been trying to brew lagers. I have to say, to date, I have not brewed one successfully. When I started brewing lagers, I would use two packets of Safale 34/70 and would pitch the yeast after allowing the wort to cool in my freezer for a few hours. The result was always a fruity bomb, regardless of the style of lager, tasting similar to a hefeweizen. I figured the problem might be the yeast, so I switched to liquid yeast, got a yeast starter kit, and started making yeast starters for the lagers. I would again cool the wort for several hours, even after initially using a wort chiller, then pitch the decanted starter. I would always have fermentation start within 12 hours of pitching. Now the lagers are diacetyl bombs. Then I figured maybe it was my fermentation. I've tried the traditional style of fermentation for lagers, allowing them to stay in primary for around 10 days, then letting them have a diacetyl rest for two days before transferring and lowering the temp to lagering temp and lagering for at least two months. I also tried the Brulosophy quick lager method and had the same results. What could be the problem of causing such a high level of diacetyl? The next lager I brew, I am going to allow the wort to sit at fermentation temp (50 degrees) over night to guarantee the wort is at the right temp before pitching the yeast. Does anyone have any other suggestions? Maybe not enough oxygen in the wort when pitching? Thanks in advance.

 

[brewbama]

http://www.professorbeer.com/articles/diacetyl.html

 

[Holybarfly]

Have you considered contamination? Do your ales ever have off-flavors?

 

[dmtaylor]

Your diacetyl rest needs to go longer than 2 days. Try a full week at warm temps. I bet the problem goes away. If not, there's no ill effects from going even longer. Even 2 weeks warm won't hurt anything.

 

[badmajon]

What temperature are you fermenting at? Primary that is.

 

[Cardassian]

Your diacetyl rest needs to go longer than 2 days. Try a full week at warm temps. I bet the problem goes away. If not, there's no ill effects from going even longer. Even 2 weeks warm won't hurt anything.

Agree with the longer d-rest.

I do a forced d test on my lagers and rest them until that is clean.
Then I lower the temp and lager. (now if only I can lager them for more than 3 weeks before tapping)

 

[casualbrewer]

I struggled with diacetyl with different lager yeast also.. Never an issue with 34/70 though. Actually just fermented it at 65 degrees and it came out great. Maybe even cleaner than usual..

 

[Beeragent]

I always ferment my lagers around 48-50 degrees. I think part of the problem is pitching the yeast before the entire wort has cooled to pitching temp. With my equipment, I just can't get the wort cooled past 80 degrees, then leaving it in the kegerator for several hours is still not long enough. Next time I'll cool the wort overnight before pitching the yeast. As mentioned above, I may also have to extent my d-rest past a week.

 

[jmark]

Don't be afraid to let it cool overnight - I routinely do that as I often can't chill below 75-80. As long as your cold side equipment is sanitary and closed, I doubt you'll have issues. I've gone as long as 24 hours before pitching without ill effects.

 

[dmtaylor]

Don't be afraid to let it cool overnight - I routinely do that as I often can't chill below 75-80. As long as your cold side equipment is sanitary and closed, I doubt you'll have issues. I've gone as long as 24 hours before pitching without ill effects.

Ditto. I'd prefer to pitch as soon as possible, but especially for those late night brewing sessions, I don't sweat it at all waiting until morning.

 

[no_borders]

I'm not an expert on brewing lagers, but it sounds like you're rushing the primary a little bit. Depending on the SG ten days isn't long enough of a ferment before a diacrtyl rest. My understanding you want to be pretty far along in fermentation before warming up, or else you're just fermenting your lager warm. If there is sugar to consume, the yeast aren't going to reabsorb diacetyl.

I usually let my lagers go at 50 degrees for 2-3 weeks before slowly ramping up to a rest temp, and then slowly cool down to lager temp. It's a long process but it's worth the wait

 

[brewerdoc]

After several years of successfully brewing ales, I've been trying to brew lagers. I have to say, to date, I have not brewed one successfully. When I started brewing lagers, I would use two packets of Safale 34/70 and would pitch the yeast after allowing the wort to cool in my freezer for a few hours. The result was always a fruity bomb, regardless of the style of lager, tasting similar to a hefeweizen. I figured the problem might be the yeast, so I switched to liquid yeast, got a yeast starter kit, and started making yeast starters for the lagers. I would again cool the wort for several hours, even after initially using a wort chiller, then pitch the decanted starter. I would always have fermentation start within 12 hours of pitching. Now the lagers are diacetyl bombs. Then I figured maybe it was my fermentation. I've tried the traditional style of fermentation for lagers, allowing them to stay in primary for around 10 days, then letting them have a diacetyl rest for two days before transferring and lowering the temp to lagering temp and lagering for at least two months. I also tried the Brulosophy quick lager method and had the same results. What could be the problem of causing such a high level of diacetyl? The next lager I brew, I am going to allow the wort to sit at fermentation temp (50 degrees) over night to guarantee the wort is at the right temp before pitching the yeast. Does anyone have any other suggestions? Maybe not enough oxygen in the wort when pitching? Thanks in advance.

I noted the follow up post where you stated that you usually brew with temp range extending up to 80 degrees. I think this is your largest problem. I posted about diacetyl and it might be helpful to you so that you can see all the factors that are well known to influence diacetyl in your beer. http://www.brewerdoc.com/diacetyl-rest/

Tip: Make one change at a time when trying to isolate where your brewing is going wrong that way you know what intervention actually made a difference.

 

[VladOfTrub]

An enzyme can be purchased which eliminates the precursor. Diacetyl rest during primary is only a temporary blow out patch, diacetyl will reform later on in the secondary, keg or bottle. Krausening is used when diacetyl rest is employed. Fast lagering of Pils or Lager occurs due to fermentation of glucose which is the native sugar in starch. Glucose is released when Alpha liquefies simple starch called amylose. Yeast rips through glucose and in 10 days fermentation is complete. For that reason a secondary fermentation vessel is not generally needed when single infusion is used. Maltose and maltriose ferment at a slower, more even rate. When wort is imbalanced, diacetyl is more likely to occur. When clean, balanced, wort is produced along with using good yeast diacetyl formation is rare.

 

[SleepyCreekBrews]

It's generally regarded that you do the diacetyl rest at approx 75% attenuation ...I suspect you're beyond 75% after 10 days.

The last time we made a bock at the brewery here, we pitched the yeast, and there was a 1-day dwell. 4 days of primary fermenting later we did the diacetyl rest for 3.5 days. Then another 5 days to finish primary, then 10 more days in secondary. then 2 months lagering in kegs and bottles.