Hmm, maybe I’ll cook it on high for 5 hours and low for 3 hours. What happens if you over cook it?
As long as you keep it covered in liquid and the fat and liquid doesn't boil away, you should be ok. I leave the fat cap on the top and take it off when cooking is over. Take the brisket out of the liquid and tent it with foil for 15 - 20 minutes before slicing (across the grain, of course). Use the remaining liquid to cook your cabbage. Low boil for 20 minutes.