Diacetyl vs. crystal/honey malt

[sictransit701]

I have a strong scotch ale about two weeks in the bottle. I know it’s young, but I like to sample. Tasted one today and it had a buttery taste. I know that could be a sign of Diacetyl. I know Diacetyl can be from infection, oxidation, or not enough time for the yeast to clean up. I have also read that it could be confused with some of the crystal and honey malts. This recipe had a lot of it. 1 lb crystal 40 and 8 oz. honey. I gave it plenty of time in the fermenter. I’m careful about sanitation and oxidation. It doesn’t have a slick mouth feel. Could this buttery taste be those malts? and will it age out?

 

[sictransit701]

By the way, it tastes like this candy, if you are familiar with that. I would describe this more like buttery than caramel.

 

[ba-brewer]

How diacetyl tastes may be a personal thing. I think I get more of a butterscotch caramel flavor from diacetyl not the fake butter thing. The same beer my wife can pick up as butter. If you know someone that drinks wine with an educated palette they might be able to tell you if it is diacetyl.

I have a bottle of imitation butter that I used to help detect diacetyl. That smells like buttered popcorn.

 

[thehaze]

I've used a lot of crystal and honey and never experienced any off flavours of this kind.

" Buttery " is usually associated with diacetyl, so ageing the beer might help get rid of it. I however am of the opinion that diacetyl is better to be removed during fermentation, so before packaging.

 

[jswillbrewforbeer]

Diacetyl can be confused for caramel/toffee and vice versa but if you say it does actually taste buttery, then it likely is diacetyl. Some butterscotch/diacetyl is allowed in this style though so it's not out of place unless it's disctracting. Might clean up a bit in the bottle but like thehaze said, it's better to resolve diacetyl during fermentation.

 

[sictransit701]

No Diacetyl taste was present when I bottled.

 

[ba-brewer]

Which yeast did you use?

I had a beer made with wlp005 that tasted fine when I kegged it but then diacetyl showed up later. It is possible to have the precursors present that will develop later.
A force diacetyl test can help identify them.
https://scottishcraftbrewers.org/?p=805

 

[sictransit701]

Imperial joystick

 

[ba-brewer]

I have not used that strain and the propaganda appears to be a fairly clean yeast, but it says it works fast and flocculates well so that is also the characteristic of yeast that can leave diacetyl.

You did not say how big your batch was but 1.5lb of crystal type malts in 5gals seems like it would be noticeable, maybe it is just the malt.

 

[sictransit701]

It’s the strong scotch ale from brewing classic styles.

 

[ba-brewer]

what was your ferment schedule, did you bump the temp as the yeast started to slow down?

 

[sictransit701]

Pitched yeast at 64*F. It was at 66*F in my fridge for 2 weeks. Then, I brought it inside the house and left it at 70*F for a week. 3 weeks total. Bottled for 2 weeks.

 

[McKnuckle]

I put some form of crystal malt into nearly everything I brew, up to 10% for some styles. Contrary to what many people seem to experience, I never get any weird flavors from it, or a beer that is too sweet. To me it just adds flavor complexity and some mouthfeel. You only have 7.7% total in a pretty big beer, it's not the issue.

The yeast you used is supposed to be the same as PacMan, which by most reports is very clean, except for this one thread (the poster had nobody corroborate his impressions, either).

 

[sictransit701]

It was clear and had reached its fg.

 

[ba-brewer]

Your ferment schedule seems like it should be fine to get the yeast to clean up.

edit: assuming the yeast was fresh and/or you made a starter. I know the impereal has a 200B cell count to start, but I think your beer might need more cells but I did not check.

 

[khannon]

Is this a 5G batch? The crystal malts are not out of line. I'm not familiar with the yeast, but assuming you made a starter for a strong batch, or pitched appropriately, I've not experienced such issues with a ~90% maris otter bill.. Temps seem fine..

Is it with all bottles? I know I had some issues with diacetyl-like(buttery, identified as such by people who know what they are talking about) in a batch, but in a bill with no crystal or honey(or M.O.), but not in all bottles, so I suspect it may have been a bottle sanitation issue on mine.

If you are sure on the sanitation, I would say give it some time..
If not, I would also say give it some time..
If you don't like it, give it to co-workers, if you do drink it yourself..

What was the starting and finishing gravities?

 

[sictransit701]

Sg 1.095
Fg 1.020

 

[khannon]

Yeah, still an amateur (back into it for ~6 years with ~60 brews under my belt, more in the past, but it was a long time ago..), but I would not be pointing at the crystal malt or honey malt for buttery(or even caramel under this recipe).
Not to question your palate, but are you getting "sweet" instead of buttery? 1.020 isn't super sweet, but might be enough to impart sweetness.. M.O. can impart "biscuit or bready" also, so maybe that is part of it?
What were you mash temps? I guessing for the style they were higher to leave some of the un-fermentables?

Do you have a local club/homebrew store with someone you can bring a sample to?

And.. I would give it some time.. My stronger beers have always benefitted from it.

 

[Tobor_8thMan]

Honey malt or crystal malt? Not in my experience.

Perhaps, these are helpful?
http://beersmith.com/blog/2012/04/21/diacetyl-in-home-brewed-beer-the-butterscotch-flavor/

http://byo.com/article/dealing-with-diacetyl-tips-from-the-pros/

 

[sictransit701]

I put some form of crystal malt into nearly everything I brew, up to 10% for some styles. Contrary to what many people seem to experience, I never get any weird flavors from it, or a beer that is too sweet. To me it just adds flavor complexity and some mouthfeel. You only have 7.7% total in a pretty big beer, it's not the issue.

The yeast you used is supposed to be the same as PacMan, which by most reports is very clean, except for this one thread (the poster had nobody corroborate his impressions, either).

Read Gordon Strongs books when doing research before this brew. He gets Diacetyl like flavor from crystal malts too. So. Maybe I have good taste buds. It’s not just me. He also mentioned his scotch ales getting dinged from judges with Diacetyl when it was actually crystal malts. A lot of brewers have mentioned kettle caramelization as giving a Diacetyl flavor.

 

[McKnuckle]

A lot of brewers have mentioned kettle caramelization as giving a Diacetyl flavor.

I'll look into this a bit out of curiosity. But my gut feeling is that "caramel" and "butter" and "toffee" probably have similar organoleptic qualities, all being in the dairy family. But that doesn't mean that the diacetyl compound itself is present. Thanks for the reference.

(Here's a thread discussing this topic.)