Originally posted March 4, 2011

One of the best meals I’ve ever had

March 04, 2011

One of the best meals I ever ate was during my first year as a postdoc at Caltech. My advisor, the unequalled Harry Gray, had been named the Swift Lecturer at Caltech. To be named the Swift Lecturer is a big deal. Normally, this honor is presented to a scholar from another university with the intention that they will stay at Caltech for a week and be accessible to students/postdocs/faculty. We had some wonderful Swift Lectures during my time there, but Harry’s was by far the best. Now, because the Swift Lecture usually comes with a big check and lots of travel expenses, there is a good deal of money involved in this process. Harry, being the generous person that he is, decided that more than anything else what he wanted was a big party at the faculty club with all of his nearest and dearest. If you know Harry, then you probably also know that if you know him then he knows you and therefore you are his friend. Also … if you know Harry, chances are very likely that you were at this party.

It was a fantastic night. Wonderful drinks (for the love of God, thankfully no “Ru-bippies”). Fantastic people. Incredible food. The main course for our dinner that night was pot roast. It was one of the best things I have ever eaten. The pot roast was tender, succulent, and comforting. Everything you could hope for in this dish, though not something you’d expect to see at a fancy affair. However, there was something “different” about the pot roast. It was cooked to medium on the inside and nicely browned on the outside. This goes against everything I expect pot roast to be and was a frontal assault on the manner in which I would judge a good pot roast from that point on. It also made absolutely no sense to me; How could you prepare pot roast this way?

Collagen

When you cook filet, you want to cook it at a high enough temperature that you brown the outside of the steak. But, you don’t want to cook it for too long and make the meat tough. Cooking meat is all about unfolding proteins. And meat is made up of the proteins actin and myosin (you guys all remember that from high school bio, right?). It turns out, that to get a cut of meat to cook to just medium, you want to unfold the protein myosin while leaving actin intact. Actin starts to unfold at around 150F/65.5C. Meat loses its tenderness when the internal temperature rises above this point. So, its a balance (cooking is always a balance). Use a high enough heat to give your steak some flavor, but don’t develop that flavor at the expense of overcooking/ruining your meat.

That’s the way it is for steaks. Stews/roasts/ribs are another matter. You have to cook these meats for a long time. When you cook them, you unfold both myosin and actin, and, yet, somehow the pot roast is still tender and succulent. But, if you try to cook stew meat the same way you cook a steak, you’re going to end up with a really chewy and tough piece of meat on your plate. What makes the two so different?

This image is from Cooking for Geeks. (Go out and buy this book.) This image shows where different cuts of beef come from and their collagen content. Note how high collagen content corresponds to the parts of the animal that are required for movement.

What cuts that you roast have that cuts you grill don’t have is the protein collagen. Collagen is a connective protein that makes up tendons, ligaments, cartilage, blood vessels and is found wrapping the muscle fibers in certain types of meat. Collagen is what makes cuts like chuck/brisket/ribs/round tough. But, collagen has a little secret. If you cook it for long enough, it will break down. It will stop being so tough. It will turn into gelatin.

An image of the protein collagen.

That’s right. The best pot roasts are so delightful because they have “jello” in them. The world’s meatiest, tastiest, most delightful gelatin in the world. Unfortunately if you are cooking in a conventional oven and in order to get the meat to this point, you need to cook it for a long time at a temperature that will unfold both actin and myosin. The result is that your pot roast is brown in color and would be completely tough were it not for the presence of the collagen turned gelatin.

My rare pot roast

Back to the case of my rare pot roast at Harry’s party. I couldn’t square this notion that roasts had to be cooked for a long time and the fact that I was eating a piece of pot roast cooked to medium-rare. What I have found out in my reading, recently is that you can cook pot roast sous-vide (under vacuum). For those of you not familiar with the sous-videtechnique, the great benefit of it is that you can hold a piece of meat at a very specific temperature (lower than you get in an oven) for a very long time. This means that you can cook a steak to a perfect medium-rare by cooking it sous-vide at 135F/57C. The only downfall here is that you have to “cook” the steak for an hour or so until the interior of the steak reaches this temperature.

It turns out that you can also cook pot roast sous-vide so that you unfold myosin and break down collagen while leaving actin intact. To do this, you need to keep your roast at 141F/61C for 24 to 48 hours. While this may be a long time to wait, there is really very little effort involved other than being patient.

Now, I don’t personally own a sous-vide set-up. They can be expensive (although you can make one yourself with a little electronics hackery). But, on the occasion of Harry’s Swift Lecture, the sous-vide cooking really did change the way I understood cooking could be done.

Cheers

-mrh