The microwave—that small appliance we imagine to be invincible against microbes. Big mistake.
In August 2024, researchers from the University of Valencia in Spain published a study in the scientific journal *Frontiers in Microbiology* that was as fascinating as it was slightly stomach-churning: after analyzing 30 microwave ovens—both domestic and professional—they identified no fewer than 101 different bacterial strains. A veritable little ecosystem hidden behind the glass door. Some of these bacteria are even classified as extremophiles—a term describing microorganisms capable of surviving conditions that would normally be lethal to most living species, such as radiation, intense heat, and repeated cooking cycles. In other words, your microwave isn't just a kitchen appliance; it is a miniature laboratory of accelerated natural selection.
Rest assured, however: the researchers note that pathogens genuinely dangerous to human health, such as *Salmonella*, do not survive in this particular microbiome. The discovery remains primarily of scientific interest, with researchers viewing it as a promising area for biotechnology research. Yet, it serves as a reminder of a simple truth we tend to forget: contrary to a persistent myth, microwaves do not sterilize their own interiors. They heat the food placed inside, not the surrounding walls. Consequently, tomato sauce splatters, soup splashes, and residues from rapidly reheated meals quietly accumulate on the walls, never being eliminated by the appliance itself.

What the task actually entails

Cleaning the microwave means tackling the interior cavity (walls, ceiling, and floor), the turntable, and the door's glass window—which is often the most neglected area, despite accumulating a significant amount of splatters. Allow about 10 minutes for a full session, including the time needed to loosen stubborn, baked-on residue, which can sometimes require a bit of patience.

Tips and tricks for effective cleaning

The best-known and most effective method is using steam: place a bowl of water mixed with a little white vinegar or lemon juice in the center of the oven, then heat it on high for 2 to 3 minutes. The resulting steam softens the residue on the walls, allowing it to be wiped away easily without any scrubbing. Lemon also has the added benefit of deodorizing the appliance—especially useful if odors from fish or spicy dishes have lingered.
As for the turntable, there is no need to struggle with it inside the oven; it is usually dishwasher-safe or can simply be washed in the sink with standard dish soap. A simple preventive measure makes a big difference: consistently covering dishes with a microwave-safe lid or a plate when reheating significantly reduces splatters, thereby cutting down on the frequency of deep cleanings.
Finally, remember to wipe up fresh splatters immediately after each use rather than letting the residue dry; once baked on, it takes much more time and elbow grease to remove.

While the Spanish study offers reassuring news regarding health, it also dispels a deeply rooted myth: the microwave does not clean itself—despite the waves, the heat, and the appliance's apparent magic. A quick, regular cleaning routine using vinegar or lemon transforms this haven for extremophile bacteria back into a perfectly hygienic appliance.