[flbrewer]

I kegged my most recent beer about a week ago and it tasted pretty decent to me a few days ago. Today after taking a sample I thought I noticed diacetyl. I'm not 100% sure that this is what I'm smelling and tasting but it's a familiar taste/smell that I've noticed in a previous beer I brewed. The recipe is below FWIW and I just want to rule out an infection that may be lingering in my equipment if that is a possibility. Any thoughts?

This beer was mashed at 151, kept under close temp. control w. controller in a chest freezer at 67 for 10 days, cold crashed and kegged.

12 lbs 8.0 oz   Pale Malt (2 Row) US (2.0 SRM)   Grain   1   93.8 %
9.6 oz   Cara-Pils/Dextrine (2.0 SRM)   Grain   2   4.5 %
3.5 oz   Caramel/Crystal Malt - 40L (40.0 SRM)   Grain   3   1.7 %
10.00 g   Chinook [13.00 %] - First Wort 60.0 min   Hop   4   17.4 IBUs
25.00 g   Warrior [15.00 %] - Boil 60.0 min   Hop   5   45.5 IBUs
20.00 g   Columbus (Tomahawk) [14.00 %] - Boil 30.0 min   Hop   6   26.1 IBUs
1.00 Items   Whirlfloc Tablet (Boil 15.0 mins)   Fining   7   -
20.00 g   Amarillo Gold [8.50 %] - Boil 10.0 min   Hop   8   7.5 IBUs
20.00 g   Simcoe [13.00 %] - Boil 10.0 min   Hop   9   11.4 IBUs
20.00 g   Amarillo Gold [8.50 %] - Steep/Whirlpool 0.0 min   Hop   10   0.0 IBUs
20.00 g   Centennial [10.00 %] - Steep/Whirlpool 0.0 min   Hop   11   0.0 IBUs
20.00 g   Citra [12.00 %] - Steep/Whirlpool 0.0 min   Hop   12   0.0 IBUs
20.00 g   Columbus (Tomahawk) [14.00 %] - Steep/Whirlpool 0.0 min   Hop   13   0.0 IBUs
20.00 g   Simcoe [13.00 %] - Steep/Whirlpool 0.0 min   Hop   14   0.0 IBUs
1.0 pkg   Safale American (DCL/Fermentis #US-05) [50.28 ml]   Yeast   15   -
20.00 g   Amarillo Gold [8.50 %] - Dry Hop 0.0 Days   Hop   16   0.0 IBUs
20.00 g   Centennial [10.00 %] - Dry Hop 0.0 Days   Hop   17   0.0 IBUs
20.00 g   Citra [12.00 %] - Dry Hop 0.0 Days   Hop   18   0.0 IBUs
20.00 g   Columbus (Tomahawk) [14.00 %] - Dry Hop 0.0 Days   Hop   19   0.0 IBUs
20.00 g   Simcoe [13.00 %] - Dry Hop 0.0 Days   Hop   20   0.0 IBUs

[klickitat jim]

It could be diacetyl, but awfully hard to say without a sample. And it can come from an infection like pediocaccus. Good way to tell is if it gets stronger over the next few days, it's an infection. Can you describe what you're tasting smelling seeing and feeling?

[dmtaylor]

Diacetyl is impossible to detect via the interwebs.    Talk to your local homebrew club and see if they taste anything off.  If I had to guess, I would doubt an ale with US-05 would have any diacetyl, although I guess it's possible.

[Frankenbrew]

There's nothing in the recipe that would mimic the flavor/aroma of diacetyl. If it were diacetyl that you were detecting, you'd perceive a definite buttered popcorn flavor. If you are not sure, it could be that it is there, and you are not that sensitive to it or it isn't there and you are just looking too hard for flaws. Your best bet is to have someone with a good palate, like a BJCP judge, taste it for you.

Did you take it off the yeast cake too soon? That might cause it, even though your process looks good.

[klickitat jim]

With 225 grams of hops not counting dry hops... its going to take someone with amazing skills to detect D unless its pretty booyaw

[HoosierBrew]

With 225 grams of hops not counting dry hops... its going to take someone with amazing skills to detect D unless its pretty booyaw

That was my thought. It's not impossible but it takes some work to get diacetyl out of 1056, especially noticeable enough to shine through that hop schedule. I wonder about possible pedio.


Edit - Though I guess you could still get the slick mouthfeel even if the beer were too hoppy to taste the buttery. Justin, describe this for us !

[ynotbrusum]

At that temp I just don't see it being a function of the US-05 - with that much hopping, maybe it is a hop related thing?  Seems too early for pedio to get much diacetyl out there....

[norcaljp]

Try switching your serving line and spout. A buddy of mine just had a problem like with a heavy hopped beer using 05 that seemed to go away when he switched lines. It's likely not the issue, but an easy thing to try just in case.

[toby]

Diacetyl is literally movie popcorn butter in the aroma.  Some people consider it 'butterscotch', but to me, it's straight up butter.  Infection based diacetyl is going to be pedio.  It will get stronger as it ages.  You could then theoretically use some brett strain to clean it up.

[flbrewer]

After reading some of the great descriptions on here, I'm leaning towards not diacetyl. Perhaps it's more of a vegetative new beer aroma and taste. Considering it finished dry, I didn't hit my OG, and it has a ton of hops, it's just not balanced and the hops are overtaking the beer.

IF it were an infection, what would I need to clean and how? I'm guessing just everything post-boil? Keg, lines, faucet, fermenter.

[narcout]

I bet it's fine. 

There are a ton of hops in that recipe, and you say you only kegged it a week ago.  Let it chill for a while.

[brewinhard]

I bet it's fine. 

There are a ton of hops in that recipe, and you say you only kegged it a week ago.  Let it chill for a while.

+1.  Next time you may want to consider leaving the beer in the fermenter on the yeast for around 2 wks prior to transferring, packaging, or cold conditioning. As clean as US-O5 is, if proper time is not allowed for the yeast to clean up after themselves, then fermentation by-products can be left behind (i.e. diacetyl, acetaldehyde). 

2 wks is a good rule of thumb to help rule out conditioning as being the culprit for most average gravity beers.
As stated above though, the beer is probably just young and needs a week to come together or so.
If it is a true pedio infection (which I doubt it is providing proper sanitation procedures), then it will increase not only in diacetyl but also with slight acidity over time revealing the true nature of infection.

With that being said, some beers can easily be packaged successfully within a 10 day time period. But just be sure they exhibit no off flavors/aromas before doing so.

[HoosierBrew]

I'd add that if there are some hop solids still suspended they'll settle which will mellow the harsh flavor. If not, sheer time will mellow the hop character. I bet it's way better in a week or two.