I've long heard that keeping baking soda in your fridge eliminates odors, and I've pretty much always had a box open in the fridge — not exactly switching it out every 30 days, like you're apparently supposed to, but just leaving it in there with the lid open.
And it's seemed to have worked: My fridge has never been particularly stinky. Recently, though, I tossed my old box of baking soda and didn't replace it. Things haven't been particularly stinky since then, either, so I started to wonder if the baking soda had been doing anything all along.
I took to the internet. The results are not just inconclusive, but surprisingly divisive! Some people absolutely swear by using baking soda to eliminate odors — anecdotes abound of people using baking soda to freshen up not just fridges and freezers, but diaper pails, garbage cans, litter boxes, and more. Others fervently call the idea of using baking soda to absorb odors a myth.
Which side is right?
The Original Tip
I'm not even sure where this tip came from originally. It's just something that moms and grandmoms have always seemed to have done! But why?
Let's start with science. Baking soda, or sodium bicarbonite, is a weak base that is also amphoteric, meaning that it can act as either an acid or a base, depending on what it comes into contact with. Inside your fridge, those stinky foods are either basic (like garlic, curry, and most fruits and veggies) or acidic (most meats and seafood, cheese, and vinegar, for example). When bits of those foods float around your fridge, things start to smell. Because baking soda is made up of millions of small crystals, each crystal provides a surface area to attract both bases and acids. So if you have enough baking soda surface area available for all of those floating food molecules, it will neutralize their odors.
There are other substances that absorb odors — like balled-up newspaper, coffee grounds, or activated charcoal — but baking soda is inexpensive, readily available, and the most commonly used solution. The key seems to be getting enough baking soda surface area to absorb all those smells, which is why Arm & Hammer (the major brand of baking soda) has created a few products specifically designed for use in the fridge or freezer.
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The Testing Method
To test the baking soda theory, I minced up some garlic and left it in a little open bowl in the fridge. After a few hours, the refrigerator smelled adequately garlic-y for my purposes. I opened a container of baking soda I had in the pantry and stuck it in there, then left it in overnight.
The fridge still smelled like garlic in the morning.
I decided to adjust the surface area. I poured some baking soda out of the container and into a medium-sized bowl (exposing more surface area!) and stuck that next to my garlic bowl. A couple hours later I checked it again, and actually, the fridge smelled less like garlic! Granted, we'd been opening and closing it quite a bit as we made breakfast, so it could have been that the garlic air had wafted out of the fridge and into the kitchen.
Even after my experiment, I'm still not sure if baking soda works. But I do know two things: I'm gonna continue to try it with a bowl instead of the small opened box method, and I won't leave open bowls of cut-up garlic sitting in my fridge anymore!
All of this leads me to one other thing I noticed on the Arm & Hammer site: They remind us that keeping your refrigerator odor-free isn't just about neutralizing existing odors — it's about preventing them in the first place. If your refrigerator is clean, meaning you've wiped up and spills and there isn't month-old fried rice fermenting on the top shelf, it's not going to get that stinky. Be sure to keep your leftovers in airtight containers and toss any rotting food and you won't have that many odors from cropping up to begin with.
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I invite you to conduct your own experiments and share your results in the comments!