[Bel Air Brewing]

Invited a good friend over yesterday. Dave is an accomplished brewer, and he worked for a brewery in Austin, Texas. He has also been awarded many medals in various competitions, so he has a good working knowledge of beer profiles.

Gave him a sample of a pale Pils that we recently brewed. He was ecstatic, saying it needs to be entered in the upcoming Bluebonnet. Clean, crisp, light, yet with good flavor and good hop character. A perfect "lawn mower" beer! But it is not a light beer, i.e., Bud Light, Miller Light, Coors Light.

Next, he was given a sample of a Fest Bier that was recently kegged. His first words were...Flawed! Do not enter this beer!
Dave said it was so easy to pick out the flaw, diacetyl, after having tried the Pils which was perfect according to him.

I tasted the sample again, and after being conscious of what he was talking about, a hint of "buttered popcorn" is evident. The beer is actually very drinkable. But does not hit the mark for what was intended.

Not sure where the error happened, but it looks like I screwed the pooch on this one.

[mabrungard]

Warming a sample of a beer also helps in discerning diacetyl.

All is not lost though. Amber Czech lager allows minor diacetyl.

[majorvices]

Don't beat yourself up about it too bad, it happens to the best of us.

I sat at a taproom last week after hearing about their "slow pour pils"and how great it was and I couldn't finish the pint. Diacetyl bomb, terrible beer.

Some people have a lower threshold to this off flavor than others. Some can't taste it at all. Others (like me) are super sensitive to it.

Usually if you let the beer sit long enough the yeast will clean up the problem (prior to packaging). Heating a sample to 165° and holing it for 20minutes or so, then cooling and smelling/tasting should tell you via sensory if the precursors to diacetyl are in the beer. Oxidation during packaging can cause the diacetyl to form.

[Bel Air Brewing]

This beer was brewed with the same technique that is always used. Never had any diacetyl issues before this. The yeast is Diamond Lager. The grain bill was Ireks Pils and Munich. Ferment temp was 50 F. A diacetyl rest was not employed, as we never do.

Normally, this off flavor is easily noticed by me. I thought it was just a bit of caramel-like flavor form the Munich malt. But Dave zeroed in on it from the first sip!

Will extended aging in the keg help? If so, might just keep this one in the freezer at 32 degrees. Or would a warmer temp help, like 40 degrees?

[MNWayne]

Why not a short D-rest?

[Bel Air Brewing]

Why not a short D-rest?

We never found it necessary prior to this. But it will be incorporated going forward.

[denny]

I think there is an important lesson here for all of us....it's difficult, almost to the point of impossible, the objectively evaluate your own beer.  Confirmation bias is powerful, and we also all have our own blind spots in tasting.

[MNWayne]

Good call. I think it's cheap insurance.

[ynotbrusum]

I think there is an important lesson here for all of us....it's difficult, almost to the point of impossible, the objectively evaluate your own beer.  Confirmation bias is powerful, and we also all have our own blind spots in tasting.

I welcome my blind spots - it lets me brew what I like, without concern over the super-sensitive!

As to diacetyl, it is something that can be resolved easily by a short warm up prior to racking to keg or other packaging.  I find that with small craft operations, oxidation is often present, even more so than diacetyl (though it is fairly common enough, too).  Pitch enough healthy yeast and diacetyl seems to be less prevalent.

[RC]

Invited a good friend over yesterday. Dave is an accomplished brewer, and he worked for a brewery in Austin, Texas. He has also been awarded many medals in various competitions, so he has a good working knowledge of beer profiles.

Gave him a sample of a pale Pils that we recently brewed. He was ecstatic, saying it needs to be entered in the upcoming Bluebonnet. Clean, crisp, light, yet with good flavor and good hop character. A perfect "lawn mower" beer! But it is not a light beer, i.e., Bud Light, Miller Light, Coors Light.

Next, he was given a sample of a Fest Bier that was recently kegged. His first words were...Flawed! Do not enter this beer!
Dave said it was so easy to pick out the flaw, diacetyl, after having tried the Pils which was perfect according to him.

I tasted the sample again, and after being conscious of what he was talking about, a hint of "buttered popcorn" is evident. The beer is actually very drinkable. But does not hit the mark for what was intended.

Not sure where the error happened, but it looks like I screwed the pooch on this one.

It's a humbling reminder for you, and all of us really, that you are not in as much control as you think. The yeast are the ones in control. It's good when this happens. It brings us back down to earth and helps us shed any hubris.

[denny]

I think there is an important lesson here for all of us....it's difficult, almost to the point of impossible, the objectively evaluate your own beer.  Confirmation bias is powerful, and we also all have our own blind spots in tasting.

I welcome my blind spots - it lets me brew what I like, without concern over the super-sensitive!

I can relate!

[Bel Air Brewing]

I think there is an important lesson here for all of us....it's difficult, almost to the point of impossible, the objectively evaluate your own beer.  Confirmation bias is powerful, and we also all have our own blind spots in tasting.

Agree 100%. That is why we enter competitions, to get unbiased, blind taste test evaluations. We actually call it "Expectation Bias". A term we learned in ground school class at United Airlines.

Note that Dave was blown away by our Pale Pilsner! He did tell me of all of our beers that he has tasted, and he has sampled many over the last 18 months, this is the first one that he detected a flaw in.

This is an ongoing learning process. And I am not too old to learn!

[hopfenundmalz]

I.have a PrePro Pilsner I'm giving up on. I brewed it, then had an operation that resulted in lifting restrictions. It hasn't turned out, so it needs to hit the drain.

[Bel Air Brewing]

I.have a PrePro Pilsner I'm giving up on. I brewed it, then had an operation that resulted in lifting restrictions. It hasn't turned out, so it needs to hit the drain.

Sorry to hear this!
But I have dumped 5 gallons down the drain before too!

[Saccharomyces]

The reality is the Pilsner Uqruell has a detectable amount of diacetyl.  It is part of the flavor profile.