Subtitles section Play video Print subtitles It's kind of unavoidable if you cut into a big juicy rare steak You're gonna get some juice. Watery, red liquid seeps out of the meat and on to the plate and it kind of looks like blood. But I have good news for people who like to eat red meat but don't like to eat blood It's not blood. It's just water plus a handy protein called myoglobin. All meat is muscle but the muscle looks different depending on what it's used for White meats like turkey and chicken come from muscles that are used in short spurts every so often but have to get moving quickly Think of the chicken breasts They don't actually use their wings very often Red meats like beef, lamb and even pork come from muscles used for long strenuous activities like carrying a huge cow around all the time Before cooking, these meats are a pinky, reddish color. Holding up a heavy cow is some serious work. Work that requires a lot of oxygen for fuel which is where myoglobin comes in Myoglobin is a special protein with an iron atom at its center, which bonds with, then stores and delivers oxygen to muscle cells It works together with hemoglobin, another oxygen carrier to get oxygen to the cells that needed. The difference between red meat and white meat comes from the levels of myoglobin in the muscle. And myoglobin protein itself is red so the more myoglobin in the cells the redder the meat appears. And that juice that's spilling out of your meat? That's a combination of water and myoglobin. The animal's blood was removed when the meat was processed. Beef is around 0.8% myoglobin and lamb has a little less at 0.6%. And all of those ads have been lying to you because at 0.2% myoglobin pork is generally considered red meat too. Chicken only has about a quarter of that amount But what about humans? Well, our flesh is about as red as red meat can get at 2% myoglobin. If you have been like steak but you don't want red juice you have options. Myoglobin is red when it's bonded with oxygen. When meat is cooked rare, up to about 60 degrees Celsius, the color stays Above that temperature, the iron atom in myoglobin loses an electron, and therefore its ability to bind with oxygen. Instead, the myoglobin forms a new molecule called hemichrome that gives medium and well done meet its brown gray color Myoglobin will also turn brown if it's exposed to air for long enough, because that makes the iron atoms lose an electron too. Which is why checking the color can be a handy way to tell if your store-bought meat is still fresh It doesn't always work though, because some meat producers add compounds that keep the meat red and the color can last way past the expiration date. But if you do end up buying that red meat and cooking it rare, I hope you enjoy your oxygen rich protein water. Thanks for asking and thanks especially to all of our patrons on Patreon who keep these answers coming If you'd like to submit questions to be answered, or get these quick questions a few days before everyone else go to patreon.com/scishow. And don't forget to go to youtube.com/scishow and subscribe.