Solved! Does Baking Soda Really Deodorize the Fridge?

Q: I need a quick fix for my refrigerator’s funky smell. Will a box of baking soda in the fridge really get rid of the odors, or is this a myth?

A: Baking soda (a.k.a. sodium bicarbonate) has occupied a place in our fridges since the early 1970s, when homeowners began using it instead of charcoal to zap odors. And baking soda in the fridge does work, to an extent, as long as you follow a few rules. Read on to learn what makes baking soda an effective deodorizer and how to best use it to refresh your fridge.

Baking soda in the fridge neutralizes malodorous food molecules.

Bad smells in the fridge can be blamed on mold, yeast, or, in most cases, decomposing foods. As bacteria feed on foods in the fridge, the food often releases stinky acidic or alkaline (basic) molecules into the surrounding air. Open the door and you may be greeted by butyric acid, a bile-scented fatty acid that arises from old butter, or amines, sour-smelling basic compounds released by meat past its prime. As an “amphoteric” compound, and a weak base itself, baking soda reacts with both acidic and strong alkaline molecules, turning them, respectively, into neutral-smelling sodium salts or considerably reducing their stench.

It’s most effective on mild to moderate odors.

If your refrigerator reeks, your first course of action should be to identify spoiled foods and throw them out. At that point, baking soda in the fridge can help reduce, even eliminate, mild to moderate malingering odors, such as those arising from expired milk or cheese. Baking soda may not be able to combat overpowering odors, like that of rotten fish. To banish such a stink, scrub down the shelves, sidewalls, and crisper bins with a white vinegar-soaked sponge.

Leave out at least a cup of baking soda in the fridge and replace it often.

It’s not enough to open the flap on a box of baking soda, stick it in a random spot in the fridge, and forget about it. The ideal conditions for baking soda as a deodorizer are:

• Pour at least one cup of baking soda into a shallow, open container, or leave the baking soda in its box with the entire top removed. Because the individual sodium bicarbonate crystals that make up baking soda must come into contact with smelly food-borne molecules to neutralize them, the more surface area the soda occupies, the more exposure it gets to the surrounding air and the more stink it can squash. A box with only a small flap open doesn’t permit many food molecules inside, so you’ll be left with a musty fridge.
• Put the bowl or box of baking soda as close to the source of the smell as possible. This will increase the odds that the fetid food molecules will land on the baking soda and spur the reaction needed to neutralize them.
• Replace the baking soda every three months. Leave it any longer and it will start to take on the smell of the molecules it reacted with, becoming a source of odor itself.

Consider these equally natural alternatives.

Other natural products can also deodorize a smelly fridge. Try any of these substitutes:

• Activated charcoal. Sold online or at pet shops in pellet or powder form, this pure carbon compound used in fish tanks to purify water can trap, hold, and neutralize smelly molecules. For best results, add one cup of activated charcoal to an open container, then place in the fridge in the general area of the odor. Replace the charcoal monthly.
• Coffee grounds. While coffee grounds won’t banish odor as well as baking soda or activated charcoal, they will reduce fridge funk while conferring a mild coffee scent. Collect the grounds, pat them dry with a paper towel, then store a cup in an open container near the source of the smell. Replace coffee grounds weekly.
• Vinegar. Thanks to its acetic acid, white vinegar can kill bacteria and neutralize bad smells throughout the house. Place a glass filled halfway with white vinegar in the fridge near the source of the smell. The initially pungent scent of the vinegar itself will dissipate within a few hours, leaving you with an odor-free fridge. Replace the vinegar every few days.