How to Prevent Grease Buildup on a Microwave

Use the vent fan before and during cooking

Grease on an over-the-range microwave mostly comes from cooktop exhaust, not from the microwave itself. When you fry, sear, or sauté on the burners below, tiny droplets of oil rise into the air and settle on the nearest vertical surface, which is often the microwave's underside, front, and vent grille. Turning on the vent fan before the pan gets hot gives the air stream a chance to capture the grease before it drifts onto the cabinet.

If your microwave has multiple fan speeds, use a higher speed for frying and a lower speed for simmering. A fan that runs quietly at a medium speed is easier to leave on for the whole cooking process. Even the best vent is only effective when it is running, so make it a habit to switch it on at the same time you light the burner. For more on choosing and using these controls, see over-the-range microwave fan speeds.

Cover food in the microwave

Inside the microwave, spatters happen when food gets hot enough to pop or boil. Covering the bowl or plate with a microwave-safe lid, vented plastic wrap, or a splatter cover catches the grease before it hits the interior walls. The FDA's safe food handling guidance says to cover food, stir, and rotate for even cooking in a microwave; following that habit also keeps the interior cleaner.

Microwave ovens can heat oily items like bacon to far higher temperatures than boiling water, according to Wikipedia, which makes splattering more likely. Use a microwave-safe container and a splatter cover that does not touch the food or the oven walls. Leave a small vent for steam so pressure does not build up under the cover.

Wipe surfaces after every use

The simplest habit is to wipe the microwave after every cooking session. A damp cloth or sponge with hot soapy water is enough for everyday film. The FDA recommends washing kitchen surfaces with hot soapy water after preparing each food item. Start with the interior, then the door, control panel, handle, and the underside below the vent grille.

If you wait until grease has baked on, you will need a degreaser and more scrubbing. Removing it while the surface is still warm is faster. For daily upkeep, a soft cloth works well and avoids scratching the finish. Step-by-step instructions are in the guides to cleaning the interior and cleaning the exterior.

• Use hot soapy water for the interior and exterior.
• Wipe the door gasket and control panel, not just the main surfaces.
• Dry the surfaces with a clean cloth after wiping.

Clean the filters and fan path regularly

An over-the-range microwave usually pulls cooktop air through a grease filter before recirculating or venting it outside. Over time, the filter becomes saturated with oil and stops capturing new grease, allowing it to blow back into the room and onto the microwave. Clean the filter on the schedule in your owner's manual; most can be soaked in hot soapy water or run through a dishwasher cycle.

If your microwave vents through a charcoal filter, replace it when it loses effectiveness. Additionally, some models have a charcoal filter for recirculated air that cannot be washed and needs replacement when it no longer absorbs odors. See over-the-range microwave filters for details. Also check the vent fan blades and the duct opening for buildup, using instructions for cleaning the exhaust blower fan.

Choose surfaces and vent systems that are easier to maintain

If you are buying a new microwave, look for surfaces that resist fingerprints and smudges. GE Appliances describes finishes that wipe away smudges and fingerprints for a sparkling clean look. Stainless steel and fingerprint-resistant coatings are common options. See stainless vs fingerprint-resistant microwave for comparison.

For an over-the-range model, the vent system matters as much as the finish. A higher CFM rating pulls more air and can reduce grease settling. Match the fan to your cooktop and cooking style; see over-the-range microwave ventilation CFM. Browse the best over-the-range microwaves to compare models.

Build a weekly routine

Daily habits prevent most grease, but a weekly check keeps the cabinet looking new. Once a week, inspect the vent grille, the underside, and the areas around the handle. If you see a film, wipe it off before it hardens. This routine is especially important if you regularly cook foods with oil, butter, or bacon.

A little prevention goes a long way. By running the vent, covering food, wiping surfaces, and cleaning filters, you can keep grease from becoming a permanent part of your microwave. For more on maintaining the whole appliance, see the microwave maintenance schedule.

What to pick for your use

Questions

How often should I clean the grease filter on my over-the-range microwave?

Check the owner's manual for the recommended interval. As a general habit, inspect the filter when you wipe down the microwave. If it looks shiny or feels oily, clean it before the next heavy cooking session.

Can I use the microwave vent fan instead of a range hood?

Yes, an over-the-range microwave's built-in fan can serve as the primary vent for your cooktop, but its CFM rating should match your cooking habits. A higher CFM fan is more effective at capturing grease. See over-the-range microwave vs range hood for guidance.

What is the best way to wipe grease off a microwave?

Use a soft cloth or sponge with hot soapy water. Avoid abrasive scrubbers that can scratch the finish. For stubborn spots, let the soapy cloth sit on the area for a few minutes before wiping.

Does covering food really reduce grease buildup?

Yes. A microwave-safe cover or splatter guard traps grease and moisture that would otherwise coat the interior. The FDA also recommends covering food and stirring for even cooking in a microwave.

Why does grease seem to collect on the underside of the microwave even when I do not use the microwave?

The underside faces the cooktop, so it receives the rising oil vapor from frying and boiling. Running the vent fan during cooktop cooking is the most effective way to reduce this buildup.