Okay, let me say up front that it was not my intention to use a rock. I had a 7# pork shoulder roast that was longer than it was thick. Too long to fit in any of my Dutch ovens. But I have a large diameter pot that isn't terribly deep but I THOUGHT it was deep enough. This recipe has you brown the meat, then roast at 450 for 30 min. uncovered. Then reduce temp to 250, cover and cook 8-10 hours, basting every hour or two. At about 4 hours, it will probably have reached 190 and then you cook on til falling apart. Well, when I went to cover the pot after 30 min., it didn't fit by a good 3/4". Went outside and got a really big rock (cat weighs 5# and it weighed WAY more than she does) and weighted down the lid. Correctly figured that after a couple of hours, the meat would have reduced in size enough that I wouldn't need the rock. I did notice that that rock retained its heat for a LONG time. Well, after 4-1/2 hours, I went to check the temp and baste...and the thing was done --- mouth-wateringly, falling off the bone done. Boy, was I surprised. So forgive the fact that I've blethered on, but I DO have a question. Do you think the rock created a convection type of environment that caused it to cook that much faster? Though it was a rectangular piece of meat, not squarish, I just don't believe that the thickness was enough of a factor. After all, it weighed almost 7#. I'd like any opinions on this. I'm definitely keeping that rock around :) And, maybe with my Costco rebate, get a bigger Dutch oven. Thanks all.
PS: I've cooked this before and the timing was the longer amount I mentioned.