Leaving baking soda in the refrigerator: Why extension specialists recommend it for lingering food odors

You open the fridge to get a glass of milk and meet with an odor you can't quite place. Many people have probably experienced this while cooking in the kitchen. Baking soda has long been used as a simple way to reduce refrigerator odors. A container of baking soda, paired with basic fridge upkeep, is a practice recommended by the University of Arkansas Cooperative Extension Service and grounded in the acid-neutralizing chemistry documented by the McGill University Office for Science and Society, not internet folklore.

This is a problem that tends to sneak up on people rather than announce itself. It shows up after a big grocery run, a holiday full of leftovers, or simply a busy week where a container gets pushed to the back of a shelf and forgotten. By the time the smell is noticeable, it has usually had days to settle into the fridge.

Why refrigerator odors develop


A closed fridge holds a variety of foods, each releasing compounds into a sealed space with little airflow to clear them out. As a result, the smell of old leftovers or strong cheese can mingle with other foods, even ones that have not gone bad yet.

Some foods tend to be bigger contributors than others, including onions, cut garlic, seafood, and leftovers nearing the end of their shelf life. Plastic containers and rubber door seals can also absorb odors over time, which is part of why a fridge can keep smelling faintly off even after the original culprit has been thrown out.

The chemistry behind why it works

Baking soda works differently from sprays and plug-ins, which simply mask odors. Baking soda, also known as sodium bicarbonate, is a weak base, and many foods, especially dairy, release acidic compounds that can contribute to sour smells in the fridge. According to the McGill University Office for Science and Society, baking soda is a base that reacts with butyric acid, the fatty acid released when butter goes rancid, and forms sodium butyrate, which produces no smell because, unlike butyric acid, it is not volatile. The smell isn't covered up; the reaction itself eliminates it at the molecular level. Other land-grant universities explain the same science behind this phenomenon. Extension specialists note that baking soda can absorb some odors and chemically neutralize acidic molecules that cause many kitchen smells.

How to actually use it in your fridge

Baking soda works best when it's exposed to the air, poured into an open container, or with the box's built-in vents flipped open, rather than sealed shut. It also helps to keep the container where it will not be blocked by other food, so air can circulate over the powder surface. The same approach works in the freezer, where trapped odors from packaged meat or other strong-smelling foods can also build up. It also helps to start with a fresh box after a deep clean or when moving into a new refrigerator.

Baking soda kept in the fridge should be treated differently from baking soda used for cooking. Once a box has absorbed odors in the fridge, keep it separate from your cooking supply and do not use it in recipes.

What baking soda can't fix on its own

If a product has expired and gone rancid, baking soda will not help unless you find and discard it. A lingering smell even after adding a fresh box is often a sign that a spoiled item is still hiding somewhere in the fridge. Extension networks point out that deploying sodium bicarbonate should be viewed as just one of the several steps that should be undertaken to ensure proper maintenance of the fridge. Cleaning up spills quickly and giving the door seal an occasional wipe go a long way toward keeping new odors from taking hold in the first place.

Replace the box regularly

It's an inexpensive, low-effort fix, just a box of baking soda, something most people already have on hand. Replacing the box every month or two, sooner if you notice the smell returning, ensures it keeps working the way it's intended to, instead of becoming an ignored presence on your shelves.

It's a convenient practice that can fit right in a dorm refrigerator, your first apartment, or even a family kitchen. Alongside proper refrigerator maintenance, it is a simple and affordable way to keep your fridge neutral-smelling.