Why You Should Always Refrigerate Used Coffee Grounds Before You Toss Them

Is there anything coffee can’t do? I’ve been drinking it every morning for years, and somehow, I only just learned that I’ve been throwing away one of the most useful parts of my daily cup: the used grounds. And no, I’m not talking about using them for composting! I found out that coffee grounds actually contain a natural compound that helps your home smell better.

As much as I’d love to chalk it up to coffee just being magical, there’s real science behind this odor-fighting trick. Coffee contains nitrogen, which helps neutralize odors rather than simply covering them up, unlike most air freshening sprays (think of it like baking soda, but with a much cozier scent!). The grounds naturally absorb all kinds of funky smells and leave behind a very light coffee aroma.

After trying it myself, I was genuinely so surprised at how well it worked. I dried out my used grounds, poured them into a jar, and set it near my trash can (which usually gives off some not-so-great smells). Within a day, that off-putting odor was completely gone, and my kitchen smelled like I had just brewed a fresh pot.

Granted, you have to enjoy at least the slightest smell of coffee to fully appreciate this home hack — but if you do, it’s such a clever and inexpensive way to repurpose something you’d normally toss.

Here’s how I did it:

1. After brewing your coffee, spread the used grounds out on a plate or baking sheet to dry completely. (This step is super important because damp grounds can get moldy pretty quickly.)
2. Once they’re dry, pour the grounds into a small open container, like a ramekin, Mason jar, or even an old candle jar. (The vessel doesn’t have to be food-safe because you’re not eating anything out of it!).
3. Place the container wherever you need a little help with odor — and that’s it!

While I used this trick for my kitchen trash, you can easily use it all over your home, from the fridge or freezer to soak up food smells, to your car if it’s starting to get musty, or even near litter boxes and pet areas. The U.S. Department of Agriculture also recommends it for stubborn fridge odors: “Sprinkle fresh coffee grounds or baking soda loosely in a large, shallow container in the bottom of the refrigerator and freezer.” That’s how you know it works!

Coffee grounds are surprisingly versatile. Besides absorbing odors, here are a few other ways to reuse them:

• Use them as a gentle scrub for pots and pans (just avoid non-stick surfaces).
• Mix with coconut oil for an easy DIY body scrub.
• Rub on your hands to help get rid of lingering garlic or onion smells after cooking.
• Sprinkle them around plants that like acidic soil, like hydrangeas or azaleas.

(And if you have any unused coffee grounds lying around, you could always cook or bake with those to make coffee-rubbed steak, coffee pudding, and more.)

I love, love, love a hack that’s low-effort, free, and actually works, and this one checks every box. It also feels really good to know I’m repurposing something instead of letting it go to waste, all while keeping my home smelling fresh. It’s a small change that’s made my kitchen feel a little more put-together, and I don’t see myself going back to artificial room sprays anytime soon.

Have you tried this hack for used coffee grounds? Let us know in the comments below!

This post originally appeared on The Kitchn. See it there: Why You Should Always Refrigerate Used Coffee Grounds Before You Toss Them