Why cook stewing meat low and slow? I know that you're supposed to cook cuts like beef chuck at a low temperature until they reach a high enough internal temp for the collagen to melt, which is why the same method wouldn't work for steak cuts that lack that collagen.

But why the low temp part? If the goal is to melt collagen, couldn't that be done just as easily at a higher temp?

Also: if there's something special about cooking the meat at a higher temp, regardless of the internal temp it ends up at, does that mean that you have to be careful when searing the meat before braising?

I had always thought that the toughness of a piece of meat depended on its internal temp, but it seems like a 200F braised chuck would taste different from a 200F skilled-fried overcooked chuck steak.
If the goal is to melt collagen, couldn't that be done just as easily at a higher temp? 


No, it won't be. 

The reaction which has to happen to the collagen doesn't go quicker when the temperature is higher. You have to get it to 68 Celsius and wait for it to happen. If it is at more than 68 Celsius, it won't happen quicker, or better, or anything. You have no advantages. 

At the same time, if you have a higher temperature, you have more trouble. First, you are wasting a lot of energy to keep the stew hotter over many hours. Second, its liquid can boil off, getting the wrong consistency. Third, if the bottom of the pot becomes too hot, it will burn on. Fourth, anything non-meat in there can suffer from the heat - vegetables can overcook, starch can burn onto the bottom, anything planty (vegetables, herbs, spices) can get its taste destroyed). 

All in all, if you can cook something on a high or a low temperature, choose the low one, it is generally better for everything. Only choose high for foods which have a narrow temperature range which is high.