Anatomy of a Steak

Having concluded my self-study course in cooking sixteen sirloin steaks, I felt ready and excited to apply my knowledge to other steak cuts. First on the list and sitting in the freezer, courtesy of a recently purchased beef share, was the T-Bone. I cooked them up in a big feast with my favorite co-chefs, Susan and Janette, who made salad, squash, and amazing roasted broccoli to accompany them. Yum! Also, Susan makes another appearance here as guest photographer.

TBone Feast!

With sixteen steaks under by belt, I really should have knocked these out of the park, but you know what? I didn’t. I slightly overdid two of them and really overdid one of them, and in the process, gained some important insight into cooking the mammal muscles we call meat.

The T-Bone steak is actually two steaks and the bone that runs between them. On one side is the strip steak, and on the other there’s a smaller portion of tenderloin steak. They’re different, because they’re different muscles, and the tenderloin is unsurprisingly more tender than the strip.

Unfortunately, I didn’t fully appreciate this until the steaks were (slightly over-) done, due to the tenderloin’s tenderness confounding my attempts at feeling the doneness of the steak. I thought they needed more time, based on how squishy the tenderloin still was, but in fact, it was just that the “feel” for doneness I’d developed was honed on sirloin, which is firmer to begin with. When I poked the strip side, I realized how done the steak was, and it was too late for medium-rare.

Plated Steak

The lesson I learned her actually ties in nicely with my recent Hipster Homesteader Post and the video about whole pig butchery. The part from the video that sticks out in my mind is when they pointed out that with industrial animal processing, people stopped eating “animals” and started eating “meat,” which did not include organs. The very name for the stuff helped to distance it from living creatures. But of course, it’s not  just “meat” or “a steak” – if that were the case, it would all cook the same. But each piece is a muscle that did something.

In the case of steaks, they were muscles that didn’t do much – that’s why they’re so tender and can be cooked this way, rather than stewed or slow-cooked like tougher, more active parts of the animal. It turns out that two long muscles right along the cow’s spine are actually the source of most good steaks, and the T-Bone has a slice of each of them.

The psoas major is one of those two muscles, and it’s known in the butcher shop as the tenderloin or “filet muscle.” You know how a vertebra is shaped? There’s the tube that the spinal cord goes through (the spinal formamen in the diagram above), and then it has a knob out to each side – those are called transverse processes. The psoas’s run along the transverse processes on the inside of the spine, closer to the guts . The psoas is responsible for moving the cow’s leg forward to take its next step, so it’s not a very robust muscle at all – it usually doesn’t encounter a lot of resistance in that motion. Hence the extreme tenderness, and the name “tenderloin,” since it’s in the loin of the cow. Sliced into steaks, it’s called filet mingon. Good stuff, and expensive for a reason – in the average 1200 lb cow, there are 8 pounds of tenderloin.

The other major steak muscle is the longissimus dorsi, which runs along the top, or skin side of those spinal processes along the vertebrae, and runs the whole length of the cow’s back. It helps the cow arch its back or move it laterally. This isn’t something cows do much unless they’re bucking, so it’s a pretty tender muscle, too. Strip steaks, rib eye, and rib roast all come from the longissimus dorsi. There’s one of these muscles on each side of the spine, just like the psoas. When hunters butcher wild game, these get called back straps.

Yes, other animals have these same muscles, and you do, too. We’re all mammals, I guess, and have all been dissected by scientists using the same Latin vocabulary. Your longissimus dorsi runs the length of your back along your spine, and you might know it as one of your spinal erectors. It helps you keep your back straight and stand upright. You have psoas major, too, but it’s in a slightly different place than on a cow, since you don’t move on all fours. You may call it your hip flexor – you use it when you raise your leg or rotate it outward, just like the cow uses it to move its rear leg forward.

So that brings us back to the T-Bone steak – it’s the psoas and longissimus dorsi together, with the bone that connects them. That bone is a piece of vertebra – the spinal column was once to the side, and the transverse process runs between the psoas/tenderloin and the longissimus dorsi/strip steak. Depending on where along the spine the steak is cut, the ratio of psoas to longgissimus will be different. If there’s enough psoas/tenderloin and it’s at least an inch thick, then it’s called a Porterhouse instead of a T-Bone, but it’s essentially the same thing. Here’s a two minute video of a butcher cutting Porterhouse steaks out of a big beef loin:

Oh, and I’m sure you’re wondering about all those sirloin steaks I was cooking – I know I was. Further down the cow’s back, the longissimus and psoas end around the cow’s hips, and the butt muscles appear. Sirloin comes from the cow’s gluteus medius. I couldn’t find anything that says what that does for a cow, but your gluteus medius is on the side of your hip, and you may know it as one of your hip abductors. It moves your leg away from the center line, which is a movement I don’t make too often, and certainly not with much force. I’m pretty sure that it’s active in stabilizing the rest of the glutes, though. Assuming a cow’s gluteus medius plays a similar function, that wouldn’t be a very strong muscle, and hence great for a steak, if not quite as tender as those dainty muscles along the spine.

This is not rocket science – it’s basic anatomy – and perhaps nearly three decades into my meat-eating is late in the game to be reaching a fuller appreciation of the intricacies of the creatures I consume, but I suppose things can’t make sense any earlier than they do. I’m going to start paying more attention to the functions of the muscles I’m eating, and poking and prodding them a bit more before I cook them so that I can get a better idea of how they’re changing as they cook. I think this will be very interesting.

Cooking those T-Bones and looking this stuff up has already been very interesting in itself. Here are the websites where I got all that information.

  • Meat Shop 101 seems to be the retirement project of a former supermarket butcher shop manager, and has a lot of good information, but not much anatomy. Some neat videos, though – check this site out.
  • An article on 4th of July steaks from a ranch in Colorado that raises grass-fed cows told me what the psoas and longissimus dorsi do and what steaks they produce.
  • The site from an Animal and Poultry class at Canada’s University of Guleph has some solid butcher’s anatomy
  • I used trusty old Wikipedia for the human anatomy, and tried to use it for bovine, but it didn’t have the details I needed in the beef articles.
  • And this site has some great butchery anatomy, including a guide to “primal cuts” – the chunks of cow that get further cut into the steaks and roasts we buy at the store. It’s also great for which muscles are in which steaks. Interestingly enough, it is the website of a restaurant in Malaysia, which got the “Best Beef Noodles in Malaysia” award in 2008. Seems pretty legit, though.

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