I'm a newcomer to the kamado world, though after a few different cooks I've more or less got to the point where I can get my Kamado Joe to the desired temperature and keep it there. This last weekend I found a piece of brisket (about 3 pounds) at my local butcher and thought I'd give that a go. I found these instructions that included use of the Meater, which I have, so thought that might work. To get to the point, the internal temperature of the meat rose to 165F then levelled off. That wasn't totally unexpected – I've learnt from other sources that on slow cooks the temperature can stagnate in the middle for a while – however it stubbornly stayed at that point. I lost some heat while wrapping the meat in butchers paper and didn't get all that heat back, which actually saw the meat temperature drop a little. In the end I had to call it a day. The meat was certainly edible and tasty, but not as tender as I was expecting.
My initial thought is that the problem was the meat, which was quite lean with very little fat through it and no marbling to speak of. Would that explain why it wouldn't break down any further and come properly tender?