More than 2.25 billion cups of coffee are consumed around the world every day. That leaves a whole lot of coffee grounds behind in homes, offices, and coffee shops. An estimated 6 million tons of used coffee grounds are produced each year, with much of that waste ending up in landfills.
Before you scrape those grounds into the trash, take a second look at them. Used coffee grounds still contain organic material, nutrients, and compounds that can be useful around the house and garden. Some can go straight into the compost pile, while others can help with cleaning, crafts, and personal care.
Here are 18 practical ways to give your used coffee grounds another job.
Fertilize Your Plants
Used coffee grounds contain small amounts of nutrients, including nitrogen, phosphorus, and potassium. According to the National Gardening Association, these nutrients can contribute to healthy plant growth.
Coffee grounds can also be added to compost, where they contribute organic matter and can help with soil structure and moisture retention. Rather than dumping a thick layer directly onto your plants, mix the grounds into compost or soil.
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Repel Garden Pests
Coffee grounds may also help discourage certain garden pests. A PLOS ONE study found that coffee grounds can have insecticidal properties, with caffeine and other coffee compounds affecting some insects and pests.
Sprinkling a thin layer around areas where you’ve noticed unwanted visitors may be worth trying. Just don’t treat coffee grounds as a guaranteed replacement for pest control, since results can vary.
Make a Natural Scrub
The gritty texture of used coffee grounds makes them useful for scrubbing stubborn grime from certain household surfaces.
Mix a small amount with water or mild dish soap and use it to scrub things such as greasy surfaces or baked-on residue. Be careful with delicate materials because the abrasive texture can scratch some finishes.
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Deodorize the Refrigerator
Coffee grounds can help absorb unwanted odors, making them handy for a smelly refrigerator. Research published in the Journal of Agricultural and Food Chemistry has examined coffee’s ability to absorb certain odor compounds.
Let used grounds dry completely, then place them in a small open container in the refrigerator. Replace them regularly rather than leaving the same batch in there indefinitely.
Make an Exfoliating Body Scrub
Those coarse grounds can also be used as a simple body scrub. When mixed with a carrier such as coconut oil or another suitable moisturizer, they can help remove dead skin from areas such as the hands, arms, and legs.
Use a gentle touch and avoid applying coffee grounds to irritated or broken skin. The goal is light exfoliation, not aggressive scrubbing.
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Make DIY Candles
Coffee grounds can add a rustic, speckled look to homemade candles. Some people also add them for a mild coffee scent.
If you’re making candles at home, follow proper candle-making safety practices and use materials intended for candle making. Avoid adding large amounts of wet grounds, since moisture can interfere with the wax and wick.
Add Them to Homemade Soap
Used coffee grounds can give homemade soap a textured finish and mild exfoliating quality. Combine a small amount with a soap base and other ingredients suitable for your recipe.
The grounds can leave behind a subtle coffee scent and are a fun option for homemade gifts. Since they can be quite abrasive, use them sparingly if the soap will be used on sensitive skin.
Make a Simple Furniture Polish
Coffee grounds are sometimes used in DIY treatments for dark wood furniture. A small amount mixed with another ingredient, such as olive oil, can help give certain wooden surfaces a temporary refreshed appearance.
Test the mixture on an inconspicuous area before treating the entire piece. Coffee can stain lighter wood, painted surfaces, and finishes.
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Use Them for Traction on Ice
If you live somewhere that gets icy winters, used coffee grounds can serve as a gritty material for improving traction on slippery walkways.
Spread a thin layer over icy areas to give shoes and boots more grip. They won’t work exactly like commercial deicers, but they can make use of something that would otherwise go into the trash.
Clean a Greasy Grill
Coffee grounds can act as a mild abrasive for scrubbing away stubborn grease and food residue from a grill.
Sprinkle damp grounds onto a cloth or sponge and gently scrub the surface. Rinse the grill thoroughly afterward so no grounds remain behind. Be cautious with delicate or coated surfaces that could be scratched.
Create a Natural Dye
Coffee grounds can give paper, fabric, and certain craft materials a warm brown color. It’s an easy way to create an aged or rustic appearance without reaching for commercial dyes.
The final shade will depend on the material, the amount of coffee used, and how long it sits in the dye bath. Try it on a scrap piece first so you can see how the color turns out.
Add Them to Your Compost
Coffee grounds are a useful addition to a home compost pile. Cornell University’s Waste Management Institute lists coffee grounds among the organic materials that can be composted.
Mix them with carbon-rich materials such as dry leaves, paper, and straw rather than creating a thick layer of grounds. A balanced compost pile gives microorganisms a better mix of materials to break down.
Try a Coffee Ground Hair Treatment
Coffee and caffeine have been studied for their possible effects on hair follicles. A study published in the International Journal of Dermatology examined caffeine and hair follicle growth.
Used coffee grounds are also sometimes used as a scalp scrub because of their texture. If you try this, be gentle and rinse thoroughly. Coffee grounds aren’t a proven treatment for hair loss, so don’t rely on them as a substitute for medical care.
Use Them for Warts
Coffee grounds are sometimes included in homemade wart remedies, often mixed into a paste with coconut oil. The coarse texture may provide exfoliation, but there isn’t strong scientific evidence showing that used coffee grounds can remove warts.
Because warts can be stubborn and may resemble other skin conditions, it’s better to treat this as an unproven home remedy rather than a medical treatment. The coffee itself also contains compounds that have been studied for various skin effects, as discussed in this article about homemade coffee.
Freshen Smelly Shoes
If your shoes have picked up an unpleasant odor, dried coffee grounds can help absorb some of the smell.
Put completely dry grounds into a small breathable pouch, old sock, or piece of fabric and place it inside the shoes overnight. Don’t put loose, damp grounds directly into your footwear, since moisture can make the odor problem worse.
Coffee grounds can also be used as a general deodorizer. Learn more about their odor-absorbing qualities here.
Discourage Cats From Garden Beds
Some gardeners sprinkle coffee grounds around flower beds in an attempt to discourage cats from digging. The strong smell may make certain cats less interested in an area.
If you try this method, use a light amount and watch how your garden responds. Coffee grounds shouldn’t be treated as a guaranteed cat deterrent, and large amounts can affect soil conditions.
Grow Mushrooms
Used coffee grounds can serve as a growing medium for certain mushrooms, including oyster mushrooms. The grounds provide organic material that mushrooms can grow on when prepared correctly.
If you’d like to try growing mushrooms at home, follow a reliable cultivation method such as this guide to growing mushrooms with coffee grounds. Freshly used grounds are best, and proper cleanliness matters throughout the process.
Polish Some Metal Surfaces
The fine texture of coffee grounds can provide gentle abrasion for certain metal items. They can sometimes help remove grime and light tarnish from brass, copper, or other sturdy surfaces.
Since coffee can stain and abrasive particles can scratch finishes, test a small hidden section before cleaning the whole item. For valuable, plated, or delicate pieces, use a cleaner made for that particular metal instead.
Used coffee grounds have plenty of potential beyond the compost bin. Some ideas are better suited to the garden, while others are handy for cleaning, crafts, or simple household projects. Just remember to dry the grounds before storing them, since damp coffee grounds can grow mold quickly.
With a little creativity, your morning coffee can leave behind something useful instead of another handful of waste.
