If you love your morning cup of Joe, it’s a pretty good bet you’re throwing out spent coffee grounds regularly. Take a look at this list, and you might discover more than a few answers for what to do with used coffee grounds!
Not a coffee drinker? These days local coffee shops offer their spent grounds for free. Find one near you, then stop by to pick up a bag or two.
Smoke out mosquitoes
According to the EPA, coffee grounds are a safe and effective way to keep pests away. The smoke from burning used ground coffee is especially effective in sending mosquitoes away because they are seriously repelled by the smell, which is quite subtle to humans. Remember this outdoor trick for your next summer barbecue.
Start with completely dry, used coffee grounds. Place the grounds in a bowl, on a plate, or other flat surface lined with foil and light them with a match around the edges, the way you would light incense. Watch this video. Add a few fresh bay leaves to amplify your repellant. Set the containers(s) upwind to get the scent moving.
Repel insects and fleas
Something else to do with old used coffee grounds—use them to repel insects and fleas.
Caffeine and diterpenes found in coffee grounds can be quite toxic to insects, which makes them effective in deterring fruit flies, beetles, and other such pests. Scatter the grinds in your garden to help create a barrier that slugs and snails do not like to crawl over.
Try this to rid your dog of fleas: After bathing, rub 1 to 2 cups of wet grounds into his fur. Rinse well. This will kill fleas and leave Fido’s hair or fur silky smooth.
How to Dry Spent Coffee Grounds
Spread the wet, used coffee grounds on a baking sheet in a thin layer and place them in a 250F oven until dry.
Cats naturally seek out bare soil to use as their toilet space, making gardens their favorite outdoor litter box. This causes damage to plants, gives off a seriously unpleasant odor, and is a very unsanitary condition.
Because they don’t like the smell, use your old used coffee grounds in the garden to deter cats from using your garden as a litter box. By regularly sprinkling used grounds in and around your garden, cats will eventually decide to find a new bathroom spot.
More than one website touts the joys of DIY coffee bean body scrub. According to Popsugar.com, “The caffeine can help diminish the appearance of cellulite, and the coconut oil will hydrate and smooth your skin to perfection.” Not bad, right? Certainly worth a try.
To make a coffee body scrub, thoroughly mix together 1 cup used (or fresh) grounds, 1/2 cup of white or brown sugar, and 1 cup coconut oil. To use, massage the scrub into wet skin to stimulate and exfoliate. Rinse with warm water. Your skin will be soft and hydrated.
Hand scrub and exfoliant
This is so easy and also super effective to clean and exfoliate hands after time in the garage or garden. Melt a glycerin soap bar in a double boiler set over medium heat. Once melted, stir in about 1/3 cup old coffee grounds. Pour into a mold and allow to cool fully. Coffee grounds are a natural exfoliant.
An impressive study on both humans and animals found that applying caffeine to the skin increases blood flow and accelerates hair growth. Here’s the routine: Before you shampoo, take a handful of coffee grounds and massage them into your scalp and hair for several minutes. Rinse away then shampoo as normal. Repeat at least twice a week. This very small amount of grinds down the sink occasionally is not likely to cause problems.
Spent coffee grounds contain nitrogen, phosphorus, potassium, and various micronutrients. When mixed in with the soil in your garden or houseplants (up to a 50/50 mix is ideal), coffee grounds will decompose releasing the nutrients. This makes for a good slow-release fertilizer to boost acid-loving plants and trees such as:
- Beech Trees
- Bleeding heart
- Blueberry bushes
- Dogwood Trees
- Japanese Iris
- Magnolia Trees
Coffee grounds help attract worms, which are great for your garden. If you love to fish and have your own worm bed, you may already know that mature horse manure and coffee grounds make the richest, finest worm bed mix. You’ll grow some mighty fine bait once you add spent coffee grounds.
If you don’t have time or need for those spent grounds right now, compost them for later. Adding compost to your garden can significantly improve the health of your plants. Coffee grounds can help increase nutrient levels and decrease the greenhouse gas emissions of your compost. This study found that compost made with coffee grounds and kitchen waste was richer in nutrients than compost made with waste alone. Another study determined that compost containing 40% coffee grounds produced the best quality compost.
According to ScienceDirect, spent dry coffee grounds help absorb and eliminate odors. Spread the wet, used coffee grounds on a baking sheet in a thin layer and place them in a 250F oven until dry. Once finished, you can store them in an open jar and place it anywhere there may be unpleasant odors in your home (kitchen cabinets, the refrigerator, the bathroom, near the litter box). Let the grounds hang out and be amazed at how much odor they absorb.
Place a bowl of coffee grounds in the refrigerator to neutralize odors. Fill old socks or pantyhose with coffee grounds, tie them off, to make air fresheners. Put them in shoes, gym bags, and drawers to deodorize. Keep a jar of dry used grounds under the sink to use as a scrub for your hands after chopping garlic or onions to neutralize that odor.
Avoid putting significant amounts of coffee grounds into the garbage disposal or flushing them down the sink as a way to “deodorize” or clean these areas. Unlike most foods, coffee grounds clump together in water creating nasty clogs that can prohibit the drains from doing their job. Coffee grounds should always go in the trash can. In a septic tank, coffee grounds will leave sediment that can eventually cause a blockage.
Ever suffered an ugly coffee stain on a clean, white shirt? Bingo! Coffee grounds offer an inexpensive, all-natural way to color cotton, rayon, linen, and paper. Simply rewet dry coffee grounds and use them to dye fabric or paper—even darken brunette hair.
Used coffee grounds for scratch cover
Make a thick paste of used coffee grounds and water. Spread this over scratches on wood furniture, then allow to sit for 10 minutes or so then wipe away with a clean cloth. Notice how the coffee has dyed the exposed wood to make it less noticeable. Need it darker? Reapply until you’re happy with the results.
Coffee contains natural acids and enzymes which are especially effective at tenderizing meat. Add the grounds to your favorite dry rub. Apply the rub to the meat at least 2 hours before cooking. The grounds along with the dry rub will get cooked into the meat creating a dark, crispy crust or “bark.”
Another option is: Re-brew the spent coffee grounds to make coffee. Allow to cool, then use it to marinate meat in the refrigerator for up to 24 hours.