Hit my 200th rack of ribs on Saturday and finally understood why my uncle in Memphis never wrapped his
I stopped wrapping at rack 150 after watching a guy in Memphis run his whole pit unwrapped for 14 hours, and my bark went from soft to something people actually ask about, so now I'm wondering if wrapping is just a crutch for people who don't trust their fire.
The wood you're burning changes everything about whether wrapping helps or hurts. I ran unwrapped on hickory for years and got great bark, then tried the same thing with apple and it came out pale and blah. Fruit woods burn cooler and wetter so the surface stays damp longer. Now I run cherry or oak for the first 4 hours unwrapped no matter what, then decide based on how the bark feels with my finger.