Babe, it’s protein: Why your meat isn’t bleeding (and never was)

You’re walking through the grocery store and spot a pack of steaks with red liquid pooling at the bottom. Or maybe you're out to eat and someone sends their food back because “it's still bleeding.”

But let’s be clear: it’s not blood. It never was.

Despite what TikTok chefs, dramatic documentaries, or that one friend who only eats well-done say, the red juice in meat is actually myoglobin—a totally normal, harmless protein mixed with water.

So before you panic at the meat counter (or shame someone for ordering rare), let’s set the record straight on what’s really going on inside your steak.

Myoglobin is an iron-containing protein that gives meat it's rich red color (plus it's a great source of bioavailable iron - no anemia here!) In fresh meat, myoglobin shows up in three forms. Let's break those down.

When there’s no oxygen present—like when your steak is vacuum-sealed right after being cut—it’ll look purplish in color. But have no fear, deoxymyoglobin is here! She’s the deoxygenated version of myoglobin. The proteins haven’t had a chance to bind with oxygen yet, so your steak is still in “just woke up” mode.

When your meat has had a chance to breathe in the fresh air (or bloom, as meat scientists call it) oxymyoglobin will be present. Oxymyoglobin gives meat the bright, cherry-red color we all look for when we're shopping in the grocery store.

Now, if your meat starts to look brown or tan, don’t panic—metmyoglobin has entered the chat. This happens when there’s very little oxygen, like when meat’s been stacked too closely or when the iron in myoglobin gets oxidized over time. Think of it as meat that’s been through some things. Character development.

This does impact the way consumers select their meat. In fact, some places discount meat that has become discolored due to the formation of metmyoglobin. People often associate the brown color with spoilage (which isn't always the case, in fact, I'll be purchasing the metmyo meat to save a few bucks).

I know, I know. "Get the chemistry talk over with, what's the deal with the juice coming out of my steak!" Well folks, news flash - 75% of your meat is water. Water mixed with myoglobin gives us something the meat industry like to call "purge." As meat ages, it goes through a process called syneresis. In simple terms, the muscle starts letting go of what once was. (Relatable, right?) The protein structure can’t hold onto the water anymore, and along with that water goes some of the iron. The result? A little juice in the package, but nothing to fear.

So you might be thinking: “Wait—iron is in blood, so isn’t this iron just leftover blood?” Fair question, but nope. Let’s clear it up.

Red blood cells contain a protein called hemoglobin, which carries oxygen in the bloodstream. Myoglobin, on the other hand, is a muscle protein that also contains iron (but it lives in muscle tissue, not in the blood). It’s what gives meat its red appearance.

There’s actually no blood in your muscle tissue. At least, not once the animal has been harvested. During processing, animals are exsanguinated (fancy word for "all the blood is removed"). After that, full sides of meat are rinsed thoroughly to remove surface blood and hung in a cooler to chill for an extended period of time before your steak is ever cut or packaged.

This chilling period allows the muscle to release excess moisture. So by the time it hits the grocery shelf, what you’re seeing is just water and myoglobin, not blood.

So the next time you see a “bloody” steak or a package with red liquid pooling at the bottom, don’t freak out—and definitely don’t toss it. What you’re looking at isn’t blood, it’s myoglobin doing its thing. Meat is a complex, living tissue with real science behind its color, texture, and moisture—not a crime scene. Understanding the difference between blood and myoglobin doesn’t just make you a smarter shopper—it makes you a more informed, less misled consumer. And bonus: the next time you're at the grocery store or out to dinner, you can casually drop the word “myoglobin” and impress your friends, family, or date with your meat science knowledge. You’re welcome.

Want to read more about the science? Check out these references!

Nethra, P. V., Sunooj, K. V., Aaliya, B., Navaf, M., Akhila, P. P., Sudheesh, C., ... & George, J. (2023). Critical factors affecting the shelf life of packaged fresh red meat–A review. Measurement: Food, 10, 100086. https://doi.org/10.1016/j.meafoo.2023.100086

Suman, S. P., & Joseph, P. (2013). Myoglobin chemistry and meat color. Annual review of food science and technology, 4(1), 79-99. https://doi.org/10.1146/annurev-food-030212-182623

Williams, P. (2007). Nutritional composition of red meat. Nutrition & Dietetics, 64, S113-S119. https://doi.org/10.1111/j.1747-0080.2007.00197.x

About the author:

Jenna is a graduate researcher, ag communicator, and current Ph.D. student who’s passionate about cutting through the noise surrounding food and farming. With years of experience studying consumer behavior and advocating for farmers and ranchers, she’s here to help you rethink what you thought you knew about your food—one myth at a time.