The three college campus fellowships of Gracepoint Fellowship Church just had the NSWN yesterday and grilled 1100lbs of meat. In a previous post, I stated that cooking the kalbi to well done actually makes it more tender. I'll explain the principles in this post.There are 2 things that make meat tough: myosin deformation/shrinkage and overabundance of collagen. It sounds technical (and it is) but it's not too hard to grasp. Let's break it down....
Muscle fibers (myosin) shrink and compress when cooked. It's like squeezing a sponge, the water leaks out and the compressed material is dense, tough, and dry. Also, it results in a gray-brown color as the red blood cells are destroyed. This occurs when crossing from medium to well done.
I mentioned collagen in a previous post. In many cheaper cuts, there is an abundance of these tough fibers called collagen. Collagen unravels as it's cooked and forms gelatin, leaving the meat tender.
Tender cuts (like filet mignon or a good ribeye) have little collagen and will be tender. You don't want to cook it past medium if you want to keep it tender.
Tougher cuts have lots of collagen which you want to break down through heat, but you want to avoid over cooking it as it will become a bit tough. That's why I like to slow cook it until medium. The long time allows the collagen to break down, but it's kept cool enough to prevent it from becoming overdone and dry.
So why does Kalbi become more tender when fully cooked? The answer is in the marinade. There are meat tenderizers in fresh kiwi, pineapple, or papaya that break down muscle fiber. When cooked to well done, the fibers shrink, but the enzyme tears up the fibers so it's not that tough, even when bound together. The high heat helps break down the collagen further. The result is broken down collagen and muscle fibers that are broken down and not tough. The more you cook it, the more collagen you break. Just make sure it doesn't dry out. Also, the cooking process helps make it a little firm rather than chewy, easier to tear apart.
So why not add tenderizer to everything? You could buy the cheapest meats and throw in some kiwi and get tender meat. Here are the limitations... marinades cannot penetrate beyond 1/2 inch thick, so you need it thinly sliced. Next, tenderizers have a tendency to cause meat to have a "mushy" texture. we don't want our meat to be mush. The enzyme breaks down meat too much usually and there isn't enough structural toughness to chew on. Imagine the difference in tenderness between a fine steak and a piece of kalbi. The steak has substance you can chew and bite into, yet you don't have to chew much. The kalbi tears apart too easily. Tenderizers are an effective way to make cheap, thin cuts of meat tender, but you can't replace the tenderness of a good ribeye steak.