When I stew beef or lamb cubes in spinach and onions and yogurt and garam masala (ground green cardamom pods, coriander, star anise, black pepper, cinnamon, cumin, dried fenugreek leaves, fennel seeds, black mustard seeds), I find that I can cook it for hours, and it always ends up with beautifully tender meat that is also bright pink. Long stewing accounts for the tenderness, but what chemical in this mixture is keeping the meat as pink as if I had cooked it rare on a grill? Have read all Robert Wolke’s books, and looked (admittedly inexpertly) around the internet, and am now turning to any cook/chemists who can tell me what chemical is doing this, and where it comes from. Much appreciated.
I don’t have the specific chemical names here. I will have to look it up when I get home but I seem to remember from Harold McGee’s “On Food and Cooking” there are two chemicals that need to combine to cause the meat to go grey. They are released and break down at different temperatures. When undergoing a fast cooking method, the heat goes up fast enough that the two chemicals release and exist at the same time and causes the meat to go grey.
With slow cooking methods, one of the chemicals gets released and is broken down before the heat rises high enough for the other chemical to be formed. It’s the same mechanism as barbecue smoke rings I think.
Huh. I’ve never had that experience. The only thing I could think of is nitrite or nitrate of some kind, but I don’t see where that could be (and that require some time of curing to soak into the meat.6
This is essentially correct (I have my copy of “On Food and Cooking” on my phone’s Kindle app).
What McGee says about this phenomenon:
He goes on in the same section to describe the barbecue pink ring, which is actually formed when nitrogen dioxide gas produced by the combusting fuel forms nitric oxide through a set of reactions at the food’s surface, and then combines with myoglobin and forms a stable molecule that is pink.
Obviously it’s been a long time since I read that section of the book. Thanks, Bump!
Interesting. I’ve never had stewed meats exhibit this phenomenon myself. Maybe I don’t do them slow enough? But even in a just a bubble-every-few-seconds simmer for four to six hours, the meat doesn’t look like a rare hunk of meat on a grill for me.
Questions and answers like this are part of what I freaking love about the Straight Dope Message Board.
God job, everyone! And thanks for telling me about that book; I have a copy on the way!
It’s an awesome book. It’s NOT a cookbook- there isn’t a single recipe or method of preparation in the entire thing.
But it is an incredible resource for knowing what’s going on with your ingredients and what’s going on as they’re prepared via all the various methods. Sort of the “ur” reference for that sort of thing actually.
It never looks rare; it looks more like say… corned beef, where it’s obviously not raw or even rare, but it’s definitely not the usual light brown/gray color of well done meat either.
Hmmm…I’ll have to have a closer look next time, as I usually eat my stew meat in one bite, but I seem to recall it always being brown-gray on the inside. Tender and fall-apart, but not that corned beef red, for sure. Like if you google “crockpot pulled beef” I don’t see any pictures where the interior is red. Or maybe I’m just thinking of a different shade of red, or something, but this color accurately reflects the interior of the meats I’ve cooked sans nitrite/nitrate.
Like I said, maybe I don’t do it slow enough or something. With my technique, I generally do bring to a boil than drop the temp to a slow simmer, so given McGee’s explanation, it sounds like that might make the difference.
I feel pretty plugged into the world of cooking and I’ve never heard of uncured meat staying red in a stew or braise.
Thanks to everyone. I haven’t seen the same effect with other slow preparations, perhaps because compared to other recipes, this one cooks both for a long time and at a fairly high temperature. My only other guess was that it had something to do with the sodium nitrate in the spinach, but there just didn’t seem there could be enough of it to produce the effect.
I was curious about whether spinach was also a nitrate-containing veggie like celery. But, I don’t know what concentrations would be necessary. I feel like an experiment is in order. 
What is curious to me is that you say this recipe cooks at fairly high temperatures, which seems to go against the McGee explanation of gradual and gentle heating.
Hmm. Turns out there’s quite a lot of sodium nitrate in spinach, and it’s pretty easy to extract by cooking it in water. So, maybe.
Hmm. I have some spinach here. Can’t do the recipe today, but may want to try for my own personal edification. Give me an idea of how much spinach, how much liquid, and how much meat is involved in this recipe, and I might try a batch with and without. That said, from my memories of curing stuff, it takes a good soak over weeks to get it all inside the meat. Like, I remember corned beef that was pink about 3/4 of the way through, but at the very center had that brown/gray color where the nitrate hadn’t penetrated. So I wonder if just cooking in it would make that much difference.
I use about 3-4 pounds of frozen spinach per pound of meat, and rarely need to add any liquid: a lot of the time involved is getting the water out without burning anything. Of course, the yogurt adds moisture as well.
I’d have thought that cooking it in a nitrite-rich solution would give you more of a barbecue-style pink ring.
Well, the actual chemical is sodium nitrate, which is converted in small amounts to nitrites in the body but not in the pot while it’s cooking. Sodium nitrate (I just learned) is called “Chile saltpeter” because it also can be and is used to preserve and fix the color of processed meats. According to the NIH report, the amount of spinach in my recipe could contain anywhere up to 10g of the stuff, though I have no idea how much of it ends up in a state that can affect the meat. And I can only report what I see: no ring, just uniformly pink, tender lamb or beef. In any event, this stuff is pretty good and I would encourage everyone to try it if they like the ingredients, whether or not the meat colors up. Don’t forget lots of salt and hot pepper.
That’s what I would have thought as well. It takes a good long while for that to penetrate. The few times I’ve home corned beef, you can tell when it just needed a few more days, as there was still a bit of a brown center left in it. It took at least ten days for a brisket flat, and more like three weeks or so for a point.
Perhaps that’s what would happen if I were stewing the piece of meat whole, rather than cutting it into 1/2"-3/4" cubes. I may try it sometime.