Why Your Steak Is Turning Brown

Has this ever happened to you? You’ve bought a piece of steak from the supermarket, or you’ve taken it out of your fridge or freezer, eager to make it for lunch or dinner. You open up the wrapping or packaging and find that the steak’s color isn’t its usual red. It instead has a brownish tone.

Keep reading to find out why your steak is turning brown and what it means.

Why Your Steak Turned Brown

Like sliced apples, the color of meat can change quickly, even if it is still safe to eat. The brownish color is caused by a chemical process known as oxidation. Oxidation refers to the process of a molecule losing its electrons.

Your steak’s red color is caused by a protein known as myoglobin, which forms oxymyoglobin when exposed to air. In the middle of this pigment, there is iron. Every time this iron loses an electron, the oxymyoglobin’s shape changes to a brown protein called metmyoglobin.

To understand why your steak turns brown, you’ll want to understand the various causes of oxidation.

Low Oxygen Levels

Your steak is in low oxygen conditions when it is wrapped or packaged. Oxygen often reacts with your steak’s myoglobin, turning it red. However, when the packaging blocks the oxygen from reacting with the protein, the steak’s oxygen levels are significantly lowered. This exposure leads to oxidation, which causes your steak to turn brown.


Sometimes the brown color could be a result of storing your steak in extremely cold temperatures.

Marinades and Salt

Your steak could have turned brown because of the marinades or salt you added to it. Many people don’t know that there are spices that can cause oxidation. Salt, for instance, is a pro-oxidant. 

So the next time you marinate your steak and leave it for a few hours or days, depending on the marinades you used, you could find that your steak has turned brown.


Different bacteria can sometimes produce metabolites like peroxides or sulfides in your steak, causing it to turn brown. Often, such bacteria can also cause your steak to have a rotten smell and a slimy texture. This bacteria is called spoilage bacteria. It usually grows when you store your steak for a long time or store it at temperatures above 40 °F.

If a slimy texture and bad smell accompany your steak’s brown color, they are signs that pathogenic bacteria are present. If this is the case, it is best not to eat the steak.

Is the Brown Steak Safe To Eat?

Contrary to what you might think, your raw steak turning brown often has nothing to do with it spoiling. If you have stored your steak correctly, or the steak you bought is not past its best-by date, then it is most likely safe to eat.

Try smelling it to determine if it has a sour or pungent smell. If it does, then you should throw it away and get yourself a fresh cut.

How To Know When Your Steak Has Gone Bad

Because of the unusual brown color, it is understandable why many people might assume that their steak is not safe to eat. There are, however, much better methods to use if you want to know whether your steak is still fresh. These methods include:

  • Checking the expiration date on the steak’s package to ensure that it has not passed
  • Touching it to feel if the steak has a slimy film on its surface that feels sticky and slippery
  • Checking to see if the steak is dry or shriveled
  • Smelling your steak for the presence of an off-putting strong ammonia odor
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Written by: Adam Wojtow

Adam Wojtow, the founder of Steak Revolution, is a true steak enthusiast. His primary goal is to help others perfect their steak-cooking skills.