> Color is a biochemical process. Pink is meat without the proteins
> denatured. Once there is no more pink, all of the protein are
> denatured and the heat energy must find the chemical reaction
> with the next highest activation energy.

Ok... but a steak isn't a fluid; heat isn't evenly distributed. While
you're still busy denaturing proteins in the middle, you must be also
binding connective fibers and making the meat tough on the outside, all at
the same time (at least with a steak of any reasonable thickness). (Not
being a food chemist, I'll take you word for it that that's what happens.)

> In specific the binding of
> connective fibers to make the meat tough. There is an amazing
> lack of overlap of the two reactions.

Why is that? This is what I don't get. It's not like losing the last of
the local pink suddenly makes that meat a much more efficient conductor,
passing the rest of the heat along to the middle where it's still needed. :-)

Of course, this is only really of academic interest for me; I like a steak
rare to medium-rare anyway (and not just because it gets tough when
overcooked; it tastes better when more rare also, for me).

> Chemistry. Heat of activation. Heat tends to flow to the reaction
> that has the lowest heat of activation.

Heat tends to flow (in a solid) according to how good a conductor of heat
that solid is. It doesn't depend on whether a low-activation reation is
waiting to the left rather than to the right. :-)


-C