30 Uses For Used Coffee Grounds (From Fertilizer To Fish)

by Scott Deans | Last Updated: April 24, 2020

Would you believe me if I told you that you can use coffee for more than making a cup of Joe? What If I told you they don’t even have to be fresh grounds? Sometimes it’s actually better to be using used coffee grounds.

Because coffee grounds have so many interesting properties like staining, smelling great (but not to unwanted pests), and being slightly acidic, they can be an extremely versatile thing to have saved up. From getting rid of unwanted odors to helping you catch fish, used coffee grounds still have so much more to give. Make sure you’re not missing out and read these 30 uses for used coffee grounds.

30 Uses For Used Coffee Grounds

1. Neutralize and Eliminate Odors

Coffee grounds are famous for being able to make a place smell better. That’s not just because coffee smells great.

Most coffee deodorizer solutions start with allowing your grounds to dry completely. It’s only once they’re dry that they are ready to de-stinkify things. You can:

One study in the Journal of Hazardous Materials turned coffee grounds into activated carbon. Activated carbon works to eliminate nasty odors by chemically binding to the stinky compounds in the air.

The method of making activated carbon also involves Zinc Chloride and a furnace. So it’s not quite a DIY at-home trick. Cool though.

2. Natural Exfoliant For Your Skin

The rough texture of coffee grounds make a great natural exfoliating agent to remove dead skin cells and dirt from your skin.

You can simply mix some grounds with water and rub it into your skin. An even better concoction would be to mix the grounds with coconut oil or your favorite soap.

Many mass-produced exfoliating skincare products contain plastic microbeads which are a terrible pollutant for our oceans. Coffee grounds will biodegrade so there will be no pollution caused by exfoliating your skin.

3. Plant Fertilizer For Your Garden

Sometimes the soil in your garden just does not have the right nutrients for what is growing there. What’s more, as plants grow in that soil, they use up nutrients that are present. Often gardens need fertilizer in order to get the best growth out of your plants.

Coffee grounds are chock full of many key minerals which plants need for healthy growth. Minerals such as:

  • Just sprinkle your old used coffee grounds on the soil around your plants. Simple as that.
  • 4. Make Brilliant Compost

    While coffee grounds make a great fertilizer you might be left with quite a lot of grounds for fertilizer left over if you’re a regular coffee brewer.

    Not to worry. Coffee grounds also make some brilliant compost.

    Compost is a completely natural process of decomposition for natural organic materials. It results in a material which is full of nutrients and minerals ideal for plant growth.

    Make sure to mix your coffee grounds in with lots of other organic materials which also decompose and compost. Mixing other organic materials such as vegetable trimmings, eggshells, grass clippings all make toward a rich fertile compost.

    5. A Natural Dye

    Have you ever spilled your coffee? It’s a real pain to clean up. Stains absolutely anything that’ll absorb it. Oh wait that could be useful!

    Coffee grounds can make a natural dye for just about any fabric that will absorb it.

    It’s an easy way to give fabric an aged look. Maybe you’ve already got a coffee stain on a t-shirt? Why not just rock the coffee stain color and dye the whole thing? Or take up knitting and dye some wool like Stewart Yarns!

    6. Shampoo and Promote Hair Growth

    Science has found that caffeine can stimulate hair growth. Coffee grounds still have caffeine in them. Put the grounds and what do you get?

    Simply mix coffee grounds into your favorite shampoo in a 1:10 coffee to shampoo ratio by volume. So if you have 50ml of shampoo, you would mix 5ml of coffee grounds, which is about 1 teaspoon.

    As well as the caffeine promoting hair growth; your head will smell like a coffee shop.

    7. Natural Hair Highlighter

    Coffee will dye fabrics, and you guessed it, coffee will gently dye your hair too.

    Whether your hair is already a dark shade or you have light hair and want to go a little darker, it’ll give your hair a darker shine. It will be a small change in tone and it’ll only last until you next wash your hair.

    Simple as that. It just takes time to let it sit in your hair.

    8. Insect and Pest Repellant

    Coffee contains compounds that are poisonous to many insects. These compounds are natural defenses which the coffee plant has evolved to protect it against being eaten by bugs.

    Coffee ground will deter all kinds of flies, beetles, slugs and snails.

    You can leave a small dish of grounds wherever you want to repel the little annoyances. Even better yet, just sprinkle the grounds on the ground and in areas you want to be beastie-free.

    This works doubly well if you’re already using coffee grounds as a soil fertilizer.

    9. Burn Coffee Grounds to Repel Mosquitos and Flies

    Are you aiming to get rid of airborne beasties? Well if you burn your coffee grounds, you’ll be putting all the compounds in coffee that bugs don’t like into the air. Mosquitos and other flies won’t want to be anywhere near you.

    There’s nothing worse than trying to soak up the sun but instead you’re being pestered by all kinds of flying insects. Here’s how best to burn coffee grounds and be free of flying insects:

    10. Cat Repellant

    Are you trying to keep cats out of your garden as well as bugs? Sprinkle dried coffee grounds all over the place.

    Cats hate coffee. Maybe that’s why they’re so lazy.

    11. Repel Fleas From Your Dog

    Coffee grounds will repel bugs on your pets as well as bugs in your garden.

    This is more of a preventative measure than a flea cure. To actually remove fleas from your fuzzy friend; best use a prescription product and contact your vet.

    If you’re already on top of your dog’s in-coat flea community; coffee grounds can make it less likely for the itchy suckers to come back.

    Just rub some coffee grounds into your canine’s coat after a bath.

    12. A Cleaning Scrub

    Do you have tough burnt foodstuff stuck to the bottom of pots and pans? Throw some coffee grounds in there along with a good squirt of detergent.

    Coffee grounds are abrasive and make an excellent scouring agent for any soap. It’s a nice way to avoid cleaning with harsh chemicals.

    Just remember that coffee does stain. So your wooden cooking spoons might end up a bit darker.

    13. Acne Treatment

    Coffee is an astringent. When an astringent is used topically on skin, and other tissues, it causes cells to contract.

    Astringent compounds are an effective acne treatment. This is because skin pores become tightened which helps to dry out oil build-up.

    While acne has lots of different potential causes; oily skin is one of the most common.

    14. Reduce The Appearance of Cellulite

    I can’t say I completely agree with this one but it is a common internet rumor. So It made the list.

    Cellulite is a lumpy texture that fat can develop. It happens when fat begins to push through the connective tissue under your skin.

    Supposedly, when you apply coffee grounds topically to your skin, the caffeine content will increase blood flow to cellulite-affected areas. Increased blood flow is supposed to help break down this fat.

    Mix some grounds with coconut oil and slap it onto your skin a couple of times each week.

    I don’t doubt that caffeine in the grounds would increase blood flow, but in my opinion, I don’t think that would be enough to remove those fatty lumps poking into the skin from below. Besides even if it did help to break down those lumps; what’s to stop more pushing on in and replacing it?

    No amount of coffee grounds will replace exercise and a healthy diet.

    15. Meat Tenderizer Paste

    Meat is made is muscle fibers. Muscle fibers are made of protein. Muscle fibers are formed in order for muscles to contract and relax.

    No one wants to eat tough meat. In order to make the meat softer; the muscle fibers need to relax.

    Enzymes, acids, salt, and just plain old hitting it, will all break down muscle fibers and help to make a softer lump of meat. The acidity of coffee can help it to act as a natural meat tenderizer.

    Mix some grounds in with your favorite dry-rub. It’ll bring in a lovely coffee flavor too.

    For bonus taste you could throw some cooled coffee on the meat to make a marinade.

    16. Natural Wood Stain

    Coffee’s potential to stain is not just limited to fabrics and your hair. Coffee can stain wood too. It can leave a nice authentic, rustic, aged color.

    To prepare your coffee stain, ready to be painted onto wood, first get a jar or container big enough for the amount of stain you will want. Mix coffee grounds with vinegar in a 1:4 ratio by volume. Leave it to mix and soak overnight

    Once your jar of coffee wood stain has soaked overnight, there is nothing left to do but sand your wood and get staining.

    17. Repair and Hide Furniture Scratches

    Coffee makes a great wood stain but what about just repairing perfectly good wooden furniture? Well coffee can help to hide those annoying scratches too.

    When wood furniture gets a nasty scratch, it can reveal lighter unstained wood inside the wooden mass.

    You need moist coffee grounds for this trick. So if you’ve already dried them out just mix in a little water until it has the consistency of thick mud.

    Paste your grounds into the scratch and give them 10 minutes to soak in and stain the scratch. Then just wipe the grounds away with a damp cloth or sponge.

    Is the scratch still too obvious? Apply some more. Rinse and repeat.

    18. Grow Mushrooms

    Mushrooms are notoriously picky over what kind of material they will grow in. You can’t just use any ordinary soil despite them sometimes growing in your garden.

    They need quite particular aspects to the substrate they grow in. Coffee grounds are an excellent option for a mushroom growing substrate. It is packed full of vitamins and minerals making ideal conditions for growing mushrooms.

    Usually you would need to sterilize your substrate but that has already been done to your grounds when you brewed them. Even easier.

    All you need is:

  • You can collect spores from mushrooms if you already have some of the mushrooms themselves. You can set mushroom caps on a surface that wipes down easily. Some glass or a mirror would work well. The spores fall out from the gills under the caps and you can see them on the glass or mirror surface to transfer them into your mixture.
  • Alternatively, gardening stores sell premixed sawdust and mushroom spores.
  • You want to collect about 2.5 pounds (a little over 1Kg) of used coffee grounds first. To get your mushrooms growing follow these steps:

    1. Moisten your coffee 2.5 pounds of grounds.
    2. Mix half a pound (250g) of sawdust into the grounds. If you are not using pre-mixed sawdust and spores; add your self-collected mushroom spores now. Mix it all up very well.
    3. Place the ground-sawdusty-spore mixture into your growing container. It could be a mushroom propagator designed for this, a bucket with cling film over it, or even just a freezer bag. Make sure there are a few air holes, half a centimeter in diameter, to allow fresh air in.
    4. Make sure the mixture stays moist. Use a spray bottle of water every day to keep the substrate moist.

    Each species of mushroom takes different lengths of time to grow. Some need to even be kept at particular temperatures, humilities, and such. If you’re not growing something easy, like oyster mushrooms, you’ll need to do your research on that particular species.

    In the case of oyster mushrooms, expect to see white patches begin to bud in about 2 weeks to 1 month.

    19. Treat Bags Under Your Eyes

    It is well known that the skin under your eyes can be one of the first areas to begin to show signs of aging.

    Two common ingredients in anti-aging cosmetics are caffeine and antioxidants. Funnily enough coffee grounds has both of those. To top it off coffee grounds even has anti-inflammatory properties.

    Caffeine can help to increase blood flow. Increased blood flow usually gives your body greater potential to transport nutrients into the area. Especially useful if you have dry or damaged skin under your eyes.

    Antioxidants help to protect your body against free radicals. But what are free radicals? Free radicals are atoms, ions, and molecules which can be particularly reactive and damaging to cells in your body. So Antioxidants stomp free radicals right out.

    To use coffee grounds to treat bags under your eyes you have a choice of mixing them with either water, an oil like coconut oil, or mixing them with some moisturizer. I recommend using a cheaper brand of moisturizer if you are to take that route.

    Add enough coffee grounds to your choice of mixer to form a thick paste. Naturally water won’t make a particularly thick paste unless it is some fine grounds.

    Apply the mixture under your eyes and leave it there for about ten minutes. I recommend doing this before a bath or shower to make cleaning it off super easy.

    20. Make Fishing Bait

    Did you know that coffee grounds are a fisherman’s friend? Just add some coffee grounds to bait worms to keep them alive longer. It’s food for the worms and a nice medium for them to live in.

    What’s more, is worms which smell of coffee seem to attract more fish. Species like bass and trout seem to particularly like coffee worms. I suppose they don’t have much of a chance of finding coffee anywhere else underwater.

    21. Cook With Coffee

    While used coffee grounds have lost most of their acidity, and they are really no use for a second brew, they still hold on to a lot of coffee flavor and aroma. Well, would you know it, used grounds still pack a punch and can make for a lovely flavor addition to your cooking.

    From meaty umami flavors to sweet cakes; there is not much which coffee grounds don’t compliment.

    For a delicious coffee ground meat rub check this out from heygrillhey.com

    I am a massive chocoholic. I’m also, clearly, crazy about coffee. Isn’t it brilliant that these two go great together?

    For a delicious coffee grounds chocolate brownie recipe, check out forkintheroad.co. Their recipe says to use all-purpose flour. I recommend using strong white bread flour. Really beat the brownie batter. It’ll develop more gluten and make the brownies gooier. Like chocolate lava.

    How about some coffee-based nibbles for guests to graze on? Try these coffee roasted sweet potato fries.

    22. Fabric Freshener

    Similar to using coffee grounds as an air freshener, you can also use them to freshen up fabrics. The trick is to dry the grounds out first and then not let them contact your fabrics.

    Once your grounds are completely dried out, just pour them in a small container. Make sure there are small holes to allow air in, but also won’t let coffee spill out.

    Pop your little coffee parcel into your cupboards and drawers. They will smell particularly fresh with a lovely hint of delicious coffee aroma.

    23. Natural De-Icer

    It might sound like a really weird one but coffee is excellent at keeping slippery surfaces, well, not slippery.

    Like sand and salt, coffee grounds help to give that extra bit of grip under your feet. On top of that, the slight acidity and mild salt content help to melt the ice. Consider that as an excuse to guzzle more bean juice when it gets cold.

    24. Blind Bake A Pie Shell

    Some pies need their fillings to be poured into pie crusts which are already baked. Have you ever tried to bake an empty pie crust? It’s difficult. Those things bubble up. You need to put something inside it to weigh the bubbles down.

    Some pastry chefs will use special cooking weights or little clay beads to keep their pie crust bubbles in check. Some people at home will use regular whole coffee beans as makeshift baking weights. It seems a bit silly to use perfectly good coffee beans when you can use something you’re going to throw away anyway; like used coffee grounds.

    Don’t worry, you’re not going to have a pie crust tasting of coffee grounds.

    Just cover your unbaked pie crust in tin foil then fill the tin foil with used coffee grounds. The coffee will weigh the pastry down and the tin foil will stop the coffee from contacting the pasty.

    It works a treat.

    25. Garbage Disposal Cleaner and Deodorizer

    An in-sink garbage disposer can be so handy but they can also get very stinky. Luckily they are another thing that coffee grounds are brilliant at deodorizing. One thing though; you don’t want to just throw grounds down there.

    You mix your coffee grounds with Epsom salt and baking soda. Check out hellonest.co for how they make coffee grounds garbage disposal tablets.

    When you have your coffee grounds balls ready, you can just pop one down there any time you start to get a funny whiff.

    26. Fireplace Cleaner

    If you have ever cleaned out a fireplace you will know it is a messy job. You start out with good intentions of getting rid of all that ash. Once you’re finished it has puffed everywhere and everything in the room is covered in ash.

    Coffee grounds to the rescue.

    Before you begin sweeping up, sprinkle used coffee grounds all over the ash. For one it weighs the fine particles down. Secondly the ash actually binds to the grounds. Ash dust will be much more controlled and, more importantly, less in your lungs.

    27. Spacing Small Seeds – Like Carrots

    If you have a green thumb you will know that planting small seeds, like carrots, can be a real pain in the butt. It seems that no matter how careful you are about sprinkling them those little suckers all clump up in one place.

    There are all kinds of gardening gadgets and gizmos you can buy online and in gardening centers. Coffee grounds give you a cheap and easy solution.

    Just mix your little carrot seeds, or any other small seeds, with dried coffee grounds. It helps to keep them separated and makes it so much easier to sprinkle with the added volume.

    Better yet, coffee grounds make an excellent fertilizer and pest repellant. You will have so many crops you won’t know what to do with all of them.

    28. Food For Cut flowers

    Cut flowers really don’t tend to last long in water alone. They need nutrients to survive.

    The usual fix is to add fertilizer or flower food to the water. But what if you don’t have any?

    Is it any surprise that coffee grounds can save the day again? Coffee grounds contain many of the nutrients like nitrogen, phosphorous, and potassium. As an added bonus, because the grounds have already been brewed, they have very low acidity so it shouldn’t have much impact on the pH of the water.

    29. Coffee Scented Candles

    Candle making is a really fun hobby and easier than you might think. What better candle smell than coffee?

    While it does require having some particular things like soy wax, candlewick, and something to pour the candles into it can still be very inexpensive to do. You could even reuse old candle wax.

    Check out the video below to learn how it’s done.

    30. Coffee Soap

    Imagine soap. But it smells like coffee.

    Soap is a surprisingly easy thing to make. It’s essentially just cooking. Different recipes call for all kinds of different oils. Really any one kind of oil will do the trick.

    The key to making soap comes down to the chemical reaction between lye and hot oil. After that, anything else you add is a bonus.

    Check out this article at Frugal Farm Wife for a lovely coffee soap recipe.

    Conclusion

    Do you know of any neat uses for coffee grounds that we haven’t covered here? Tell us all about it in the comments below. We really do want to hear about it.

    Can you guess what keeps me up at night? You guessed it! Copious amounts of coffee beans. What? I brew them first.