First AG doesn't taste right, any ideas?

Hey everyone, this is my first post but I've lurked around here for quite some time and couldn't imagine building my coffin keezer without the threads here on HBT.

I chose a recipe online and made some changes to it in order to fit what I could find at my LHBS.

This was my first BIAB all-grain after 9 years of brewing from extract off and on. I was hoping for an ESB but it has some off flavour that I cant put my finger on, hoping someone here might have an idea as to whats causing it.

Here's the recipe,

10 lbs 12.0 oz Pale Malt (2 Row) US (2.0 SRM) Grain 1 84.3 %
1 lbs Caramel/Crystal Malt - 40L (40.0 SRM) Grain 2 7.8 %
1 lbs White Wheat Malt (2.4 SRM) Grain 3 7.8 %
1.00 oz Centennial [8.50 %] - Boil 60.0 min Hop 4 29.9 IBUs
1.00 oz Goldings, B.C. [3.90 %] - Boil 20.0 min Hop 5 8.3 IBUs
0.50 oz Fuggle [3.90 %] - Boil 5.0 min Hop 6 1.4 IBUs
1.00 oz Fuggle [3.90 %] - Boil 0.0 min Hop 7 0.0 IBUs
1.0 pkg SafAle English Ale (DCL/Fermentis #S-04) [23.66 ml] Yeast 8 -


I brewed in primary for 1.5 weeks until reaching a stable s.g. for a few days and then let it sit in my keezer in a keg for 2 weeks before tasting. I can't single out what the off flavour is but something doesn't taste right.

 

After tasting again I feel it has a butterscotch taste, I think it could be Diacetyl that I'm tasting. I've never had the issue before but my F.G. was a little high at 1.021, could a stuck fermentation cause an excess of Diacetyl?

And no I'm not sure on the make-up of the water but I haven't had any issues in the past. I will be kegging a chocolate porter in a few days and see how that goes. If that one is off too I will have to look into the local water.

Thanks, There's a great community here at HBT

 

I don't think it's your recipe. What was your mash temp?

Can you please share your pitch temp and the fermentation temp profile (where you started it and finished)?

 

Maybe a dumb question, but have you used Fuggle hops before? They have a distinct earthy dirt mossy taste (IMO) that somebody on HBT described as tasting like a grave I dry hopped an english brown ale with them awhile back (also used them as flameout hops in the recipe), and was pretty turned off by it until several weeks later when the hop flavor mellowed out a bit. I don't think I'll use them again as finishing hops... Could that be the flavor you're tasting?

 

This was my first time using Fuggle hops, I read how they were earthy but I didn't expect it to be this much I guess. I think that its likely that that is what I'm tasting though.

I mashed at 156F for 90 minutes. I pitched at 70F and fermented at 68F.

 

You probably had some mild to moderate ester production from S-04 at those temps. Next time, pitch it at 60-62*F, start ferment at 64. After it slows down, 68 is great to finish.

For an ESB, I'd have probably done the ounce of Goldings at 15 and left the Fuggles out (or at least left off the ounce at flameout). With time, some of that character may fade away.