Explain the changes in beef as it is roasted to a medium rare degree of doneness. Include in your answer an explanation of the changes to the following variables: color, tenderness, flavor, muscle proteins, connective tissue, and fat.

There are actually six established levels of steak doneness when a beef is roasted to medium rare until done.

Explanation:

1. Blue rare 115° F: a blue rare steak is seared on the outside, to brown the meat without cooking inside. The stake is so fresh that the beef inside has not undergone the protein breakdown of longer cooking, the meat tends to be chewy.

2. Rare 120°F: a rare steak should have cool, bright red center, browned outside and the meat should be almost as soft as and springly raw meat. It is because the cooking process is so fast it does not have time to melt all the fat in the meat.

3. Medium Rare 130°F: It is the most popular level of doneness, the medium rare stake should have a warm center, nice brown crust on the outside. The meat should be pink with a hint of red in the middle. Because of the longer cooking, that renders the fat down. So it adds flavor and gives a buttery smooth texture to the meat.

4. Medium 140°F: It loses hint of red, and the meat should be pink and firm all the way through. The longer cooking period of medium stake, makes the meat drier and less tender.

5. Medium Well 150ºF: The stake might have a little hint of pink in the center, but most of the water has evaporated, and some of the fat has started to leak out. Very fatty steaks usually survive this process better than leaner cuts.

6. Well done 160° F: It is known as the chef's bane. It has had all the water, and most of the fat evaporated out of it, leaving the meat dry and tough.