This Is Why Your Can Opener Is Always Rusty

Take a closer look at your can opener. What do you see? If the answer is gunky gears, food particles and rust, then you’re not alone. I love cleaning (give me a podcast and a dirty kitchen, and I’m happy), and even I neglect my can opener. Dealing with a rusty can opener is one of those kitchen tasks that’s out of sight, out of mind, like crumby toaster trays or the inside of a microwave.

But once you’ve seen how gross your can opener is, you can’t unsee it. I’ll walk you through why it’s rusty and, most importantly, how to clean it.

What causes a rusty can opener?

The main cause of rust on your can opener is water. Here’s a brief chemistry lesson: When iron and oxygen combine in the presence of water, they create iron oxide, or rust. That’s why exposing a can opener to moisture for too long (like sitting in a humid dishwasher) will cause rust. Food particles don’t help either, because all that buildup in the gears and other crevices traps water and causes corrosion. That leads to, yep, more rust.

How do I remove rust from a can opener?

As you probably already know, rust and food shouldn’t mix. The U.S. Department of Agriculture (USDA) says, “Rust is not a food safe material, so it should not be ingested. If you see rust on the surface of a utensil such as a cast-iron skillet or knife, remove all the rust before using it.”

The most efficient way to remove rust from your can opener is with an old cleaning standby: white vinegar. I love using vinegar to clean things like stained baking sheets and my wood cutting board. The acidity works wonders while also being food-safe.

Here’s how to clean a rusty can opener with vinegar:

1. Fill a Mason jar with enough white vinegar to submerge the rusty part of your can opener (often only the gears are rusty).
2. Place the can opener in the vinegar and soak for about five minutes. Extend the time if your can opener is super dirty.
3. Take the can opener out of the vinegar and scrub with a small brush dipped in the vinegar. I like to keep an old toothbrush under the kitchen sink for jobs like this.
4. Continue scrubbing with vinegar and rinsing until the can opener is clean. Dry thoroughly with a cloth.

How can I prevent rust from forming on a can opener?

Once your can opener is sparkling and rust-free, keep it that way with proper maintenance. Clean your can opener after every use, but don’t put it in the dishwasher—the humidity and steam will lead to more rust. Instead, give it a quick rinse under hot water, and scrub with a brush and a little dish soap to clean all the hard-to-reach areas. Once it’s clean, the most important step is drying. Air-drying is not enough. Dry the can opener completely with a soft cloth before storing. Remember, moisture equals rust!