This leads me to believe that significant oxidation occurred, and as @Dgallo stated above you could have fusels from hot fermentation. For temperature "control" I try to cool my wort to the lowest temperature stated for the yeast I'm using, and then let the temperature naturally rise to whatever...
Was the off flavor apparent while you were bottling? From what I understand metallic flavors typically come from dissolved metals in the wort/beer. I'm assuming the color was lighter when bottled and has turned darker. If that's the case it would point toward oxidation.
How do you measure the color of the beer? If you're looking through a pint glass then it will be darker than the estimated SRM. AFAIK the SRM measurement is done with a 1/2" sample.
In my opinion I would rehydrate a pack of yeast just for insurance and pour the slurry into the bottling bucket with the beer. I'd hate for you to bottle the beer and not have any carbonation due to dead yeast. As far as the beer itself goes it should be fine although the yeast may be autolysing...
The "stated" attenuation was in the low 70's so I was fairly surprised when it came in so low. In my mind 152°F is the middle point of mash temps 148°F is the low end and 156°F is the high end so you should be safe at 150°F. At 72% attenuation you'll be looking at 1.014 which is around where I'd...
I would definitely recommend mashing low, I mashed in at 143°F and raised it to 154°F doing a recirculated BIAB. I believe that's why I was able to get my FG so low. The corn sugar will dry the beer out a bit and I assume that's why you'd want to add it. You might think about adding the sugar at...
I had this happen with a 1 gallon batch and was worried about an infection. It turned out fine although they didn't last long. The real kicker is trying to fish the stopper out. I eventually put the carboy and all in the recycling bin. RDWHAHB
A few weeks ago I made an accidental Scottish Heavy with WY 1728.
Grain Bill:
4 Lbs. Muntons Scotmalt
3 Lbs. Munich Dark (9°L)
8 Oz. Flaked Barley
8 Oz. Caramunich III
2 Oz. Roasted Barley
Ended up with an OG of 1.046 and an FG of 1.005 for an ABV of ~5.4%.
For hops I used an ounce of Fuggle...