I opened my SS fermenter last night and saw this black ring at the top. http://imgur.com/a/XnMLo I have this in a fridge that also houses a tiny heater for when I need to get my temps up past 70. The beer sitting in the fermenter looks fine. I’ve felt the outside of the fermenter during warm up sessions but it never felt hot so I can’t imagine this being burnt krausen but I honestly have no idea.
I don’t think it’s burnt from the heat during fermentation. I get that sometimes even with cooler fermentation. It’s just darker matter getting pushed out of the beer that made it’s way to the top of the krausen. Drying probably made it look darker.
Agreed. Looks pretty normal to me. If you get some fuzziness on it, then you have an issue.
I think that’s typical in stainless. I get that black ring as well.