by robgunby » 03 Apr 2014, 14:58
How much is needed depends on a lot of variables, so the first thing I would say is get lots in, better to have more than you need than run out. It will vary depending on the type of fuel, quality and condition of fuel, ambient temp, wind conditions, how you manage your cook etc.
As a rule of thumb, large cuts like brisket, pork shoulder etc take about 1.5 hours per lb, so you'd likely be looking at 16-17 hours for that chunk (remember this is just a guideline and you should always work to internal temperature of the meat). I use restaurant grade charcoal and usually get through, at a rough guess, 4 kg on a really big cook, in my UDS.
Personally I try not to let myself have less than one full 12kg bag of charcoal on hand. I've just opened my last bag recently to use a small amount of coal - next time I do a big cook I will go and buy some more before I cook, even though what I have will see me through a cook, I just hate running out!