Me and my friends have been cooking a 2kg=4.5 pounds piece of rumproast in a bbq smoker. We cooked it at about 250°F for about 3 hours. After that we, wrapped it in tin foil, raised the temperature to about 300°F and cooked it for an additional 3 hours. Our thinking here was that we can raise the temperature a bit, since the moisture can't escape anyway because it's wrapped in tin foil.
We were hoping for a juicy and tender roast, that "tears apart" easily with a fork. At the end it wasn't tender and it was so dry that we were afraid it would suck the moisture out of the air… When we unwrapped the tin foil there was a lot of liquid (juice), that should've probably stayed in the meat? Was the temperature too high or wasn't the cooking time right? Is this even an appropriate piece of beef for "low and slow" smoking?
Best Answer
That cut of beef is OK for 'low and slow' however, you did not provide 'low and slow.'
At 300, even wrapped, the internal temperature gets high enough that it will expel moisture. This is happening at the tissue/cellular level, so the wrapping won't stop that.
The thing that could have helped is to keep it wrapped and let it cool to almost room temperature. As the meat cools, the structure relaxes and some of the moisture could have been drawn back in to the roast.
Your theory of part wrapped, part unwrapped is fine, just keep the temperature down to 200 - 250 max. Use a rub and slow smoke. There are many BBQ charts and books and guidelines, but 4-5 hours at 225 sounds about right for that hunk. You could also section it down to two smaller pieces and you would have more control.