Why do I need to cook Grass-Fed Beef different than grain-fed beef?

You must understand, cows out on pasture, 100% Grass-Fed cows, are NOT THE SAME as cows confined to feed-lots! Though they are both called cows, they are really an entirely different type of animal, much like you might say an athlete is compared to a couch-potato. From flavor to texture, due to the way the animal was raised, both the nutrition and the lean-to-fat ratio is different. That's because cows on pasture graze (they constantly move!) from one end of the pasture, to the other, all day long, then she rotates pastures, walking from one pasture to another, enjoying choice grasses along the way. She's not just standing around getting fat (and lazy) as she eats her daily allotment of processed foods and grain. Therefore the muscle mass is leaner because she's moving! Also, grain adds fat, whereas grass provides for leaner protein. Because of this, you cannot cook grass-fed beef like you would grain-fed beef.

Protein cooks at a different rate of speed than fat. Think about cooking a fried egg ... what cooks fastest? The whites, right? They have a higher level of protein than the yolks. The yolk is known to be higher in fat and therefore it cooks slower. So when cooking lean Grass-Fed Beef, it is high in protein and it cooks fast.