How to Clean Baffle and Grease Filters: The Soak Method and How Often

Grease filters are the first line of defence in a kitchen exhaust system. They catch grease before it reaches the duct and fan. When they clog, airflow drops, smoke lingers, and more grease slips past into the parts that are hardest to clean. Cleaning them regularly is the cheapest maintenance a kitchen can do.

Baffle filters and mesh filters

Baffle filters are made of angled stainless steel or aluminium plates that force the air to change direction, so grease drops out. Mesh filters are layers of aluminium mesh, more common in lighter commercial use and in home range hoods. Stainless baffle filters tolerate stronger degreasers; aluminium needs a milder product.

The hot soak method

1. Remove the filters once the hood has cooled
2. Fill a sink or soak tank with hot water and a kitchen degreaser suited to the filter metal
3. Soak the filters fully, long enough to soften the grease (often 30 minutes or more for heavy build-up)
4. Brush along the baffles or mesh with a soft brush to lift the loosened grease
5. Rinse with hot water until the water runs clear
6. Let the filters dry completely before refitting them, with the baffles facing the right way

Avoid scouring pads that scratch the metal, and do not put aluminium filters through strong caustic soaks. If grease has baked on for months, one soak may not be enough. Our exhaust filter cleaning service degreases and inspects filters before returning them to service.

How often to clean grease filters

• High-volume frying, grilling or wok cooking: often daily to weekly
• Moderate restaurant cooking: weekly to every two weeks
• Light or occasional cooking, including home kitchens: about monthly

These are rules of thumb. Look at the filters: if you can see a grease film or the slots are clogging, it is time. Filter cleaning does not replace cleaning of the hood, duct and fan, which follows its own schedule. Use our kitchen exhaust cleaning frequency calculator to plan the full system.

When to replace a filter

• Bent or warped baffles that no longer sit flat in the hood
• Holes, tears or crushed mesh
• Corrosion that does not come off with cleaning
• A filter that is the wrong size and leaves gaps around the edges

Frequently asked questions