Forrest Posted March 23, 2021 Report Share Posted March 23, 2021 What is the blue residue on the lid?I don’t know, I’m no scientist. Even when I have used the smoke foil method I have got discoloration.Sent from my iPhone using Tapatalk Quote Link to comment Share on other sites More sharing options...
Tyrus Posted March 23, 2021 Author Report Share Posted March 23, 2021 Carbon steel turns a bluish color upon heating to a high temp, I can attest to that because I just burnt in two woks prior to seasoning them it's referred to as an oxide layer. It can be removed, but why would you. The pot stays dimensionally stable under the conditions I placed it under for low and slow. I believe Forrest used his under higher temps without any adverse affect, hope this clears up the dirt. 1 Quote Link to comment Share on other sites More sharing options...
Tyrus Posted March 23, 2021 Author Report Share Posted March 23, 2021 (edited) The burn in and oxide layer aid also in the prevention of rust Edited March 23, 2021 by Tyrus 1 Quote Link to comment Share on other sites More sharing options...
GrillnBrew Posted March 23, 2021 Report Share Posted March 23, 2021 15 hours ago, Forrest said: I don’t know, I’m no scientist. Even when I have used the smoke foil method I have got discoloration. Sent from my iPhone using Tapatalk When not grilling and brewing, my day job is a chemist, that is why that residue on the lid of the pot caught my eye. I was incorrect when I said there shouldn't be any copper in stainless steel, it is used in some grades, so that would explain the copper sulfate as I guess the grade of SS used in a sink strainer is not quite the same as that used in the smoker pot. I am familiar with the bluing, and yes that is quite normal, and I think it is great that you guys did jump in with your explanations, shows how helpful this group can be, so thanks for that. And passivating, I remember doing that with the brass ball valve on my first boil kettle before upgrading to all SS parts, I can still smell the vinegar. 2 Quote Link to comment Share on other sites More sharing options...
Forrest Posted March 23, 2021 Report Share Posted March 23, 2021 GnB, I haven’t got any off smells from the smoke or off flavors in my food. Just clean smoke! It is possible the sink strainer may not be totally stainless steel even though it states that is the material on the website of the manufacturer of the part. I tested it and it doesn’t seem to be magnetized.Maybe if there is any of this so called copper sulphate it probably isn’t enough to effect my health or flavor of my food.Sent from my iPhone using Tapatalk 1 Quote Link to comment Share on other sites More sharing options...
GrillnBrew Posted March 24, 2021 Report Share Posted March 24, 2021 Forrest, if it is copper sulfate, it will stick to the metal and should be easily wiped off. It wouldn't affect your smoke or your flavor and definitely not get into the food. Not a cause for concern, more of me being a science nerd and getting excited when I saw you had done a chemistry experiment. Now I have to try to duplicate it when my smoker pot shows up. 3 1 Quote Link to comment Share on other sites More sharing options...
tony b Posted March 26, 2021 Report Share Posted March 26, 2021 Steel, when heated to high temperatures, like in the firebox of the KK, will discolor like that. No worries. 1 Quote Link to comment Share on other sites More sharing options...
