Metallic taste on finish of my stout

[Tiber_Brew]

Next time you could try one of those silicone baking sheets to toast coconut. If the metallic taste is gone, that pretty much confirms it.

Glad to help. Hope we found the issue.

 

[bkboiler]

tried to read entire thread to see if this was mentioned, but was your immersion chiller possibly the cause? it's copper i assume.

 

[Dunkelbiertrinker]

I've got a 9.5 % abv stout with the same unsettling flavor. Everything else about the bier is great. The smell, the creamy full mouthfeel etc, But that aftertaste is not nice.
I brewed on 10 Dec 2016. Bottled on 14 Jan 2017, I too used 50g whole organic espresso beans, 3 days into primary. It was my first time adding something after it's in the fermenter. So I baked the beans at around 200*C in the oven for 10 minutes. I didn't want to add any wild yeast or bacteria and ruin the Bier. Maybe I've inadvertently ruined ... well it's not ruined, but it takes a little getting use to, by the 3 bottle, one barely notices LOL, but maybe by baking the beans I added some extra acids that taste metallic.

Water from a special fountain in Switzerland. I used it for my very first bier (a Cooper's stout kit with mods) and it was delightful, everyone loved it.
Recipe:
1 Cooper's Stout kit.
500g dark brown sugar
454g Lyle's golden syrup
201g Molasses
OG 1.082 FG 1.009
primed: 160g DDME, 10g BDME, 10g table sugar in 1 liter boiled water, added to bottling vessel.
55 x .5 L bottles.