Re: First Brisket .......help neededHere is some info from the America's Test Kitchen website. It explains what happens as a brisket is cooked. I thought it quite informative and thought I'd share it.
Making a Tender Brisket
Most cooked briskets are dry, but they are not tough. In contrast, if you cook a steak the way you cook a brisket (that is, until very well done), it will be dry and tough. What makes brisket different?
To find out, we used a Warner-Bratzler meat shear, a device designed to measure tenderness in meat. It uses a motor to push a piece of meat across a dull blade while a simple scale measures the required force. We first cooked very tender meat (tenderloin) in a 3 1/2-hour braise until very well done. Tender when raw, the meat was, according to the meat shear, 188 percent-2.9 times-tougher after braising. Next we cooked the brisket, which, unlike the tenderloin, was tough to begin with. By the end of the first hour of braising time, the meat had become even tougher. But further cooking reversed this trend. When the brisket was ready to come out of the oven (after 3 1/2 hours of braising), it was 28 percent more tender than when raw. What was happening?
The muscle fibers in meat contract and tighten soon after cooking commences. When the muscle fibers contract, they expel moisture and the meat becomes tougher. As the internal temperature of the meat climbs, a second process begins that helps reverse this trend. A tough connective tissue, collagen, begins to melt, turning into soft gelatin. In some cuts of meat, most of the toughening of the muscle is counterbalanced by the conversion of collagen to gelatin. We could see this when we used the meat shear on the brisket. Early measurements showed large variations, and if we looked at the blade after getting a high reading, we almost invariably saw white material-the collagen-streaked along the side. Once the temperature of the meat passed 200 degrees, however, these streaks had disappeared, and the meat had not only softened but also become more uniform in texture.
Extended cooking destroys tender cuts with little collagen (like the tenderloin) as they steadily give up their juices and become drier and tougher. But extended cooking actually improves the texture of tough cuts with lots of sinuous collagen (like brisket). Yes, they lose juices and become dry, but they also become tender as the collagen melts. So if your brisket seems a little tough, put it back in the oven! -John Olson, Science Editor