Ive be been brewing an coopers english bitter got Bout 3 days now at a constant temperature of 68F. My OG was 1.032, I checked it today and it was at 1.020 and I tasted it and it tasted still pretty flat but did have carbonation and had a hint of a metal aftertaste. I looked at the brew and it did have some dark brown pieces on the top. Anyone know if all these symptoms are normal?