What Are Coffee Grounds And What Can You Do With Them?

We explore what are coffee grounds and explain how to use them in your garden, at home, and for baking.

What are coffee grounds?
Coffee grounds are the leftover results after the brewing process

Used coffee grounds are the leftover results after the brewing process. Sometimes, spent coffee grounds stick to the inside of your coffee maker. Used coffee grounds clump at the bottom of your cup in other situations.

Don’t just put coffee grounds down the sink, though. Leftover coffee grounds contain numerous minerals that are suitable for a variety of surprising use cases. They’re also relatively easy to recycle.

Can You Reuse Coffee Grounds?

Used coffee grounds are the byproducts of the brewing process. They look like small leftover grains, needles, or beans visible after brewing a morning cup of coffee. Even though many people throw use coffee grounds away, you can use them creatively.

You can use spent coffee grounds to fertilize your yard, remove toxic metals from your soil, start a compost pile, and keep insects out of your yard or garden. Therefore, consider putting spent coffee grounds to work for you! You don’t necessarily have to throw them away.

1. As Fertilizer For Garden Plants

Most garden soil lacks the required nutrients for optimal plant growth. Azaleas, radishes,  hydrangeas, and some acid-loving plants enjoy coffee grounds because of their acidity. Flowers absorb nutrients from the soil.

Over time, the soil gets depleted, and flowers lack essential nutrients.

Coffee grounds contain numerous minerals essential to the growth of flowers. A few key examples include chromium, magnesium, phosphorus, calcium, iron, potassium, and nitrogen. 

You can also use coffee grounds to absorb heavy metals that might otherwise contaminate the soil. If you want to take advantage of coffee grounds in your garden, sprinkle them into the soil near your plants. To be safe, don’t overdo it on the coffee grounds.

A 20% soil-to-ground ratio is about right.

Plants that like coffee grounds include blueberries, cabbage, gooseberries, hollies, peppers, potatoes, mushrooms, and radishes. The acidic nature of coffee grounds can turn hydrangea plants blue! They will even attract earthworms to your flower bed, improving its health.

Some seedlings and plants dislike coffee grounds as they raise their PH levels. Examples include clovers, lavender, and orchids. Please check beforehand or avoid adding the grounds to your garden if you have any doubts.

Learn more about using coffee grounds as fertilizer.

2. Add Coffee Grounds To A Composting Bin

Coffee shop owners often use coffee grounds as part of a composting process and donate the results to farmers. So, try this approach if you cannot immediately put coffee grounds to work in a garden.

If you add compost to your garden or yard, you can trap water and nutrients in the soil and improve the overall health of your plants. If you decide to try a DIY compost bin, this natural process takes organic material and turns it into a rich, dark material or mulch. 

Add other food scraps to your compost pile or worm bin alongside coffee grounds to get the most out of the composting process. Examples include shredded newspaper, eggshells, leaves, grass clippings, herbs, stale bread, and even waste from fruits and vegetables.

Avoid adding grease, oils, dairy products, fish, or meat to your compost pile. As this decomposes, it could threaten the rest of your compost pile. 

3. Try Spent Coffee Grounds As A Repellent

What are coffee grounds and what can you do with them?
Sprinkle used coffee grounds around your outdoor seating areas

Are you tired of insects and pests, like snails and slugs, threatening the health of your yard or garden? Spent coffee grounds can keep them away. There are several compounds in coffee, such as caffeine, that you can use to keep insects away. Caffeine and other compounds are toxic to some pests that threaten your garden’s health.

In addition, you can use spent coffee grounds to deter beetles, fruit flies, ants, cockroaches, and mosquitoes. If you want to put your coffee grounds to work this way, sprinkle used coffee grounds around your outdoor seating areas. This should keep these pests away from your home. 

4. For Cleaning

Coffee grounds can work wonders for cleaning. Since they’re so acidic, they work best for cleaning extra grimy pans. To do this, soak a sponge in water.

Then sprinkle some coffee grounds on your sponge to make a coarser surface, and you can freely scrub away at your pots and pans.

You can also unclog a drain with reused coffee grounds, as long as it’s a minor clog. Mix the coffee grounds with boiling water. You don’t even have to worry about damaging your pipes using beds. 

It’s an excellent way to save money on home cleaning products.

5. To Hide Scratches

To use coffee grounds for scratches, make sure the color of the grounds matches the color of your scratched wood furniture.’ It’s easy to use grounds to hide blemishes. You’re staining the wood, so they’re less visible.

Mix the coffee grounds with more water to create a thick paste. Then, rub the wet grounds across the scratches. Let the coffee grounds sit on the scratch for a minute, then wipe them off.

You can use a soft cloth to wipe off the used grounds. One that won’t scratch your furniture any further. You’ll have to repeat this process several times to get the color dark enough to hide that awful scratch.

6. To Hide Unpleasant Odors

The smell of dried coffee ground can do wonders for bad odors. Dried grounds won’t only cover the smell but also absorb the odor. Coffee grounds can eliminate some of the worst smells in your home.

If your garbage or compost pile is extra stinky, sprinkle over some dry coffee grounds to wipe out that smell. You can even use them to deodorize a refrigerator. Place them in an open container in your fridge as an alternative to baking soda deodorizer.

The scent can also create a pleasant, fresh coffee smell in your home at all times. Make it a potpourri mix for your living room or bedroom. Remember that the coffee grounds must be dried to work as an odor eater.

The best way to do this is by baking them. 

7. For Your Baked Goods

Are you an avid baker? Consider throwing some coffee grounds into your next batch of chocolate baked goods. Or make some delicious coffee cake. Our favorite is to throw it into breakfast baked goods for a coffee taste.

You don’t have to stick to baked goods, either. You can also make some yummy meat rubs and spices with a touch of coffee grounds. Baked goods that work well with used coffee grounds include coffee cake, bread, cookies, and mocha brownies.

Remember, the amount of coffee grounds and acidity dramatically affects the flavor.

8. As A Good Body Scrub

A white woman applying left over coffee grounds to her hand
Reuse coffee grounds to make a body scrub at home

If you can’t get enough of the coffee smell, reuse coffee grounds to make a body scrub. Once dried, the coffee grounds have a coarse texture to exfoliate your skin. They’ll get rid of all that dead skin.

You don’t need a bunch of chemicals to make your body scrub. You can use your home ingredients or get them at your local grocery store. And remember to reuse coffee grounds once you’ve made a delicious pot of coffee.

You can make a yummy-smelling body scrub with coffee grounds, organic brown sugar, and melted organic coconut oil. Mix everything, and you’re good to scrub away!

9. As a Shiny Hair Rinse

Is your hair looking a bit dull? Do you want to boost your hair growth? Reuse coffee grounds and make a delicious-smelling hair rinse. Before we get started, we don’t recommend this for anyone with light-colored hair. The grounds can dye your hair.

The darker the color, the darker it can dye, even if it’s only temporary.

This hair rinse is best for anyone with brown hues in their hair. Your special hair rinse needs to be cold when you use it. The first method involves mixing the grounds with water.

Spray bottles make the application easier and less messy.

Don’t rinse the ground mix out of your hair right away. Put your hair up in a towel for about half an hour. Then feel free to rinse it out with warm water.

Another way to reuse coffee grounds is by rubbing the cold, wet ones into your hair and scalp.

After you’ve applied the coffee grounds, rinse your hair. Make sure you clean your shower or bathtub immediately, especially if it’s a bright white surface. It can stain if it sits on a surface too long. 

10. As Fish Bait

According to the fishing website Gone Outdoors, spent coffee grounds work quite well as bait for fish. Fishermen place wriggling worms into a container full of coffee grounds and let them acquire a coffee scent and flavor. The wriggling coffee-flavored worms are more likely to attract a good catch of bass or trout!

11. To Remove Fleas From Pets

Insects, including fleas, hate coffee rounds. After shampooing your dog or cat, rub the grounds through their coat and then wash that off. It’s cheaper than using flea repellent.

That said, we found this use case messier and more time-consuming. It’s also best to check with your vet first, as some dogs may eat the grounds, which is toxic for their health.

12. To Clean Pots and Pans

The coarse acidic nature of coffee grounds lends itself nicely to cleaning a dirty pot or pan. First, scrub the coffee grounds into the surface of your pot or pan. Use an abrasive cloth or dishrag to clean or remove dirt as normal.

Then, rinse the pot or pan to remove the coffee grounds. It’s similar to cleaning a home utensil with vinegar.

13. For Farming

Fun fact: Researchers found that adding an equal amount of horse manure to coffee grounds negates potential negative side effects and promotes a healthy harvest. They wrote, “…coffee grounds are useful to enhance long-term crop growth, short duration weed control, and soil improvement in agricultural fields by considering the inhibitory effects on the plant growth for half year after the application.”

Farmers regularly use this approach, although the smell of horse manure probably doesn’t lend itself to most home gardens!

14. For Fortune Telling!

This use case is more of a novelty act or party trick. However, consider the fact that many wannabe fortune tellers read people’s tea leaves to make predictions about their future. Well, if your guests prefer a morning brew, consider reading their coffee grounds instead.

Can You Brew Coffee Grounds Twice?

Used coffee grounds and  a cup of coffee
Re-using coffee grounds don’t taste good and look pleasant

You brew a second cup of coffee from spent grounds but don’t expect it to taste good or look pleasant. The brewing process extracts essential oils from coffee beans. If the coffee grounds do not have any oils left, your next cup of coffee will be weak and watery.

Still, re-using grounds is handy in you’re out of coffee beans for a morning brew. For more brewing advice, check out our roundup of the best coffee grounds for a cold brew.

Author

  • David R

    Job experience includes extensive work as a teaching assistant, tutor, and guest lecturer and extensive employment in the healthcare field. Have published multiple research papers and numerous poster presentations on various healthcare research topics.