Most people, when they roast a piece of meat in their oven, expect the internal temperature of the meat to rise slowly, but steadily, from the time they put the meat into the oven until the meat is ready. However, if you slow cook a piece of meat like a pork butt or a beef brisket which has lots of connective tissue in it, you will observe that the internal temperature of the meat steadily rises for a while, but then it stops. It will stay at some temperature, perhaps even fall a few degrees, for a very long time and then resume climbing. What you are witnessing is the temperature plateau which occurs when the meat gets to the internal temperature at which all that connective tissue starts to break down and evaporative cooling starts to occur.
When you slow cook a butt or a brisket, the collagen in the meat will be converted by the heat into gelatin. If you took high school chemistry, this is sort of like fractional distillation. At first all the heat going into the meat is raising the temperature of the meat. However, when you reach somewhere in the vicinity of 150-170°F, the connective tissue in the meat (collagen) begins to convert to gelatin. It takes a lot of energy to do this, so now all the heat going into the meat is fueling this conversion and no heat is available for raising the temperature of the meat. In fact, the temperature of the meat can actually go down a few degrees. However, once the conversion is mostly complete, then the heat that is going into the meat is once again available for raising the temperature of the meat and the temperature once again begins to rise.
But now science also tells us that evaporative cooling is the main contributor to the plateau or “stall”. As moisture in the meat is converted from liquid to gas, a large amount of heat is consumed to produce this conversion. This evaporation of water consumes enough heat that there is little heat left for raising the temperature of the meat.
Typically, if you cook an 8-pound pork butt low and slow, it might take anywhere from 15-20 hours for the internal temperature of the meat to reach 200°F, the temperature when it will be moist, tender and pullable. It might take 3 hours for the meat to reach the plateau temperature and another 3 hours to rise from the plateau temperature to the finished temperature. For the remaining 9-14 hours, the meat’s temperature will hover around the plateau temperature. This is when you need to be patient. If the heat of the cooker is too high and you try to force the meat through the plateau, you can do it, but the conversion of collagen to gelatin will be incomplete. This is a bad thing because this conversion from collagen to gelatin is what turns the tough dry meat into moist tender meat. The gelatin is what makes it moist!
Post time: Aug-24-2022