How to Make a Coffee Grounds Ashtray That Eliminates Odor

If you live with someone who smokes indoors—or just want to cut through the stubborn stink of stale smoke—then you’ve probably tried sprays, candles, and open windows. But there’s a surprising, low-tech way to tackle that lingering odor right at the source: coffee grounds.

Yes, used coffee grounds placed in your ashtray can actively reduce cigarette smells and help snuff out butts faster. Designer Ryohei Yoshiyuki built a working ashtray using just coffee grounds for this exact purpose.

Why Coffee Grounds Neutralize Odors

Coffee grounds are highly porous and naturally absorb airborne molecules—including the volatile compounds that make up smoke and other household odors. This absorption ability makes them effective as both a deodorizer and a moisture regulator. Their coarse texture also helps suffocate embers, aiding in quicker extinguishing of cigarette butts.

Everyday Uses for Coffee Grounds as a Deodorizer

You don’t need a special ashtray to put coffee grounds to work. Here are some common household uses that leverage their odor-fighting power:

• Toilet freshener: Place a small dish of coffee grounds in the bathroom to absorb unpleasant smells.
• Shoe deodorizer: Fill a cloth pouch with coffee grounds and tuck it into shoes or shoe cabinets. For stronger results, place the pouch directly inside footwear.
• Wardrobe and cabinet moisture control: In areas prone to dampness, coffee grounds act as a natural dehumidifier while adding a light scent.

The Coffee Grounds Ashtray Design

Japanese designer Ryohei Yoshiyuki took the natural deodorizing properties of coffee grounds and applied them directly to a functional object: the ashtray. By layering spent coffee grounds at the base of an ashtray, his design does two things: it reduces the lingering smell of smoke and helps extinguish cigarette butts more effectively than a bare tray. While no commercial product is mentioned, the concept is easily replicable at home.

How to Make Your Own Coffee Grounds Ashtray

You can create a simple, effective coffee-based odor-control ashtray with items you likely already have:

• Choose any heat-resistant container (ceramic, metal, or heatproof glass).
• Add a thin, even layer (about 0.5–1 cm thick) of used, dry coffee grounds to the base.
• Optional: Line the bottom with a coffee filter or fine mesh to help contain the grounds while allowing airflow.
• Use as you would a regular ashtray. Replace the coffee grounds when the scent fades or they become saturated.

This setup not only cuts down on smoke odor but also aids in putting out cigarette butts thanks to the absorbent and insulating qualities of the coffee material.

Frequently Asked Questions

Do coffee grounds actually remove smoke odor or just mask it?

Coffee grounds chemically absorb many of the volatile organic compounds (VOCs) that cause smoke odor—they don’t just cover it up with another scent. Their porous structure traps odor molecules, making them a true deodorizer, especially for tobacco smoke.

Can I use fresh coffee grounds, or do they have to be used?

Used coffee grounds are ideal because they’re already dry and have absorbed some moisture and aroma during brewing, enhancing their deodorizing ability. Fresh grounds may still work, but dried used grounds are more effective and readily available.

How often should I replace the coffee grounds in an ashtray?

Replace the coffee grounds once they become visibly damp, overly darkened with ash, or when you notice the smoke odor returning. Typically, this is every few days with regular use, or sooner if the smell lingers.

Is it safe to use coffee grounds in plastic ashtrays?

It’s better to use a heat-resistant, non-plastic container—like ceramic or metal—to safely hold the warmth of cigarette butts and avoid melting. If using plastic, ensure it's heat-resistant and never place hot ashes directly onto the plastic surface without a protective barrier like a foil liner or coffee filter.

Can I use this method to get rid of other smells in my home?

Yes. Coffee grounds are effective at reducing odors in shoes, fridges, bathrooms, closets, and even pet areas. Just place them in a small open container or breathable pouch near the odor source.

Recommended FrontStreet Beans for Filter Coffee

Pair your coffee-ground ashtray trick with a great cup using FrontStreet Coffee’s Ethiopia Yirgacheffe, known for its bright lemon and jasmine notes, or the Colombia Huila Supremo, offering caramel and dark cherry tones. For something deeper, try the Guatemala Antigua with its chocolate and spice profile. These single-origin beans highlight coffee’s natural aromas, making it easy to see why its grounds work so well as a deodorizer. Freshly roasted within 5 days · Orders placed before 17:00 ship the same day · Next-day delivery across most of Guangdong Province.