Decoding Tough & Tender Cuts

Understanding the basic anatomy of one mammal -- a cow, a pig, a woolly mammoth, or a rabbit -- will help you develop an instinctual sense for which cuts of meat to use in almost any situation. Most of us already have a general awareness of how animals move, and, in order to determine which cuts are which, it's helpful to think about how certain muscles may have had to work throughout the animal's lifetime: Was it a hard-working, high-activity muscle (legs, cheeks), or a lazy, low-activity muscle (back, loin)? 

If you can answer that question, it will help you determine how long to cook it, and at what temperature, in order to achieve a whole range of results. In general, muscles that work harder will be tough, while muscles that work less will be tender. That's because muscles that work hard have a lot of collagen. Collagen (and a little elastin) keep the muscles together and attached to the bone. So it's not surprising that hard-working muscles need a lot of collagen to do their job, or that this collagen makes them tough. But given enough time, heat, and moisture, this collagen will transform into gelatin. And gelatin and melted fat give slow-cooked tough cuts like smoked brisket their wonderful succulence.

Take cows, for example. Cows spend much of their time chewing, so their cheeks develop a lot of tough collagen. To make those cheeks tender, you need to cook them for a long time at a low temperature, like 140 °F / 60 °C for 72 hours, or for an hour in a pressure cooker at 250 °F / 121 °C. Likewise, beef shanks, chucks, and rumps do a lot of work, and need a lot of time or heat to get tender. But the muscles in the middle of the cow's back don't do much at all, so that's where you find tender, juicy cuts like filet mignons and NY strip steaks. A great way to memorize which muscles are tough and which are tender is to remember that, beginning with the center of the cow's back, and moving down and outwards along its body from there, the muscles go from most tender to most tough.