The Many Uses for Coffee Grounds
Coffee is by far my favorite morning drink. Espresso is my weakness and a cup of iced coffee is a great afternoon pick-me-up. In a day, I grind and drink far more coffee beans than probably any human being should. Trashing all those coffee grounds seems like a sad fate for my favorite bean. So, what can I do with the coffee grounds?
Coffee grounds are a gift that keeps on giving. You can brew ground coffee beans and drink a cup of coffee full of energy and antioxidants, but the positive properties don’t stop there. Both fresh coffee grounds and used coffee grounds have a variety of great uses. You can raise the acidity in your garden, grow mushrooms, kill weeds, repel mosquitos, and clean your pots and pans. But that’s not all!
We’ll show you what to do with coffee grounds in the garden, kitchen, shower, and how to take them backpacking on the trail. So sit back with your fresh cup of coffee and check out these tips, tricks, and hacks.
What to Do with Coffee Grounds in the Garden
Plants are like people, some like coffee and some don’t. We may not agree with every plant’s opinion but we have to respect it. Here are some ways to use coffee grounds in your garden in ways that all your plants should appreciate.
Add Coffee Grounds to the Compost Bin
Coffee grounds are high in nitrogen as well as other minerals that benefit plant growth such as potassium, calcium, magnesium, phosphorus, iron, and chromium. While coffee grounds can do a lot of good for your garden, dumping your used coffee grounds directly on your plants may not be the best approach.
Grass and other green leafy plants in your garden thrive on nitrogen and so they will most likely thank you for the addition of coffee grounds to their diet. Earthworms love to eat coffee grounds, too!
However, even used coffee grounds may retain some acidity, which means your more sensitive plants may not like a direct-dump approach.
By adding coffee grounds to a compost pile, you can keep any leftover acid in check while maintaining the right nitrogen and carbon ratio. Typically, you want your worm bin to be about 30 parts brown matter (carbon) to every one part green matter (nitrogen).
Even though coffee grounds are brown in color, they are considered a “green” addition to your compost bin because of their nitrogen. If you are adding a lot of coffee grounds to your compost, eggshells can help balance out all that nitrogen with more calcium.
By adding the right amount of coffee grounds to your compost, you can create a well-balanced mix that all your plants should appreciate. Go ahead and throw in the coffee filter, too, while you are at it!
Change the Color of Your Hydrangeas
If you are not into creating a compost pile, you should be able to add coffee grounds directly to a hydrangea bed. Hydrangeas like soil that has a pH between 6 and 6.5 (slightly acidic). This means that used coffee grounds which are also slightly acidic may be one of these flowers’ favorite drinks!
Also, if you succeed in increasing the acid in your soil, you can transition your pink hydrangeas into purples and blues. However, gardeners suggest that even a hydrangea bush doesn’t need to be fed coffee grounds more than 2 or 3 times a week.
Feed Azaleas and Blueberries
Azaleas (or, if you prefer, rhododendrons) and blueberries can take about as many coffee grounds as you choose to give them. These plants like acidic soil, and generally won’t refuse coffee.
Some gardeners even suggest adding fresh coffee grounds to the soil around these plants if you really want to increase the soil acid. Used coffee grounds will have a neutral to slightly acidic pH, which may not be enough for these acid-loving plants.
So, if you have coffee grounds that have lost their freshness, that you don’t want to drink, but hate to throw out, try feeding some of it to your azaleas and blueberries. They should be happy to take it off your hands.
Make “Coffee Ground Tea” for Orchids
Orchids also like coffee grounds but are a bit more delicate about their drink than other flowers. Orchid growers recommend you make these flowers “coffee ground tea.” To make this coffee-tea, you’ll be making a sort of cold brew out of used coffee grounds.
- Take a measuring cup of used coffee grounds and add water until the grounds are covered.
- Allow this mixture to sit for 24 hours and then strain out the grounds.
- Then add 3 parts of soft water to this coffee tea and keep it in a jar.
Serve this coffee ground tea to your orchids about once a week by pouring it on the base of the plant and not the leaves.
Kill Your Weeds
Used coffee grounds can help your flowers grow, and at the same time, can kill your weeds! What witchcraft is this?
To keep the weeds down, you should spread spent coffee grounds about 1 inch thick in your beds. Just remember that if your plants aren’t all hydrangeas, azaleas, and blueberries, you’ll want to keep the layer of coffee grounds away from their root systems. This should also prevent snails and slugs from taking over your garden.
You can save your used grounds in the refrigerator until you have enough to cover your bed. Or, you can go to local coffee shops or Starbucks and ask them for extra spent grounds to cover your garden. Coffee shops will usually be happy to set you up with used coffee grounds for free.
Make a Mushroom Miracle-grow
Did you know that mushrooms are almost as big a fan of coffee as I am? You can grow both oyster mushrooms and shitake mushrooms directly in used coffee grounds. Here are some simple steps to follow.
- Add coffee grounds to the bottom of a container.
- Drill holes in the bucket halfway between the layer of coffee and the top of the bucket.
- Add your mushroom spawn with sawdust and cover the top of the bucket with perforated cellophane.
- Spray the coffee ground-mushroom spawn mix once a day and let the mushrooms grow in a dark area.
In less than a month, you can put a shitake mushroom stirfry on your menu… with an iced coffee for dessert.
How to Use Coffee Grounds as a Pest Repellent
Besides helping your garden grow, coffee grounds can also keep the pests away. Cats, mosquitos, and fleas are not fans of our favorite bean. By adding a bit of coffee in your outdoor areas, you can reclaim your porch and garden.
Say No to Cat Poo
If you notice that the neighborhood cats are using an area of your yard as a litter box, start dumping your used coffee grounds in that area. Most cats have a natural aversion to coffee and will avoid areas that carry a strong coffee scent. So, when you put your freshly used coffee grounds in their favorite litter box corner, this is the equivalent of telling the cats, “This restroom is out of order.”
Mosquito repellent and DIY Coffee Candles
Mosquitos don’t enjoy the fresh smell of coffee. So, if they get a whiff of the scent, they may just take their party elsewhere. The EPA, suggests burning coffee grounds will give you the best result for creating a mosquito-free safe zone. You can place your used coffee grounds in a heat-resistant dish and light the grounds like incense.
Or, you can make a DIY coffee candle.
- To make a coffee ground candle, simply glue a candle wick to the bottom of your votive or an old coffee mug.
- Melt your palm wax in a saucepan on the stove at medium to high heat. Layer your used coffee grounds with the wax.
- You can even place a few coffee beans in the top layer for a nice aesthetic.
To make your candle more potent and repellent, you can add a few drops of cinnamon or peppermint essential oils. These scents can blend nicely with your coffee scent.
Flea repellent
If your dog or cat is having trouble with fleas, you can wash your pet with coffee grounds along with their regular shampoo at bath time. Fleas hate caffeine, so this natural repellent can be useful if your cat or dog can’t shake the fleas. It should also feel good on your pup’s skin!
However, this coffee ground body wash should not be used as a replacement for any flea treatments that your vet recommends for your furry friend.
What to Do with Coffee Grounds in the Kitchen
Used coffee grounds can also be useful in the kitchen. You can clean your pots and pans or make a delicious meat marinade. Coffee grounds can also work as a deodorizer in your home.
Clean Pots and pans
Coffee grounds are abrasive and make a great substitute for steel wool when you want to clean the grease and burned food off your pots and pans. Add a few grounds to your sponge and scour away.
Coffee grounds can also be useful for cleaning your cast iron cookware. Since degreasing detergents can ruin the seasoning on your cast iron, you can scour your skillet instead with coffee grounds. The grounds will also be easier on your hands than the chemicals in kitchen detergents.
Make a Meat Marinade or Rub Using Coffee Grounds
Coffee can make a tasty marinade or rub. Using fresh coffee grounds can add extra acidity and tenderize meat. Or, if you don’t want to waste your precious supply by cooking with it, you can use used coffee grounds as a spice rub along with paprika and salt.
Your leftover cold coffee also doesn’t have to go to waste. You can use it to marinate meat and make it more tender. Simply soak your meat cut in coffee for half an hour to two hours before cooking it. This can add a great flavor and make your meat even juicier.
Deodorize Your Fridge
Dry your used coffee grounds and use them as a natural air freshener. You can set a dish of coffee grounds in your fridge to absorb the smells. This will leave your food tasting fresher.
You can also deodorize your microwave by putting 2 tablespoons of coffee grounds in half a mug full of water. Heat the water for about 30 seconds, and you can rid your microwave of those funky smells.
Dried coffee grounds can even freshen up the air in other areas of your house. Put the grounds in a dish on top of a bathroom cabinet, or at the bottom of your potpourri bowl in your living room.
What to Do with Coffee Grounds in the Shower
Fresh or used coffee grounds can also be healthy for the hair and skin. Using coffee grounds as a body scrub can give you smoother skin and reduce cellulite.
DIY Body Scrub
You can use either fresh coffee grounds or dried used coffee grounds to DIY your own body scrub.
- Combine equal parts coffee grounds, melted coconut oil, and brown sugar.
- Rub the body scrub on problem cellulite areas and let the coffee ground mixture soak in for 5-10 minutes.
- Then rinse it away with a mild body wash.
This natural exfoliator will help you get rid of dead skin and have your skin looking and feeling fresh! Fresh fine coffee grounds are best because they will be easier on the skin than a coarser grind.
DIY Coffee Shampoo
Adding coffee to your shampoo routine will leave your hair, shiny, soft, and smooth. The antioxidants in coffee also stimulate the cells in the scalp which means that a coffee shampoo can also help to prevent hair loss.
- Just add 1 spoonful of used coffee grounds to the amount of shampoo you are planning to use.
- Mix together and rub this combination into your roots.
- Let it sit for at least 5 minutes before rinsing it out.
For extra shine, you can add a teaspoon of baking soda to this recipe.
Treat Puffy eyes
If you have had too many late nights and want to get rid of those tell-tale bags under your eyes, coffee can help! Pat cool coffee grounds gently under eyes. Leave the grounds for 10 minutes then rinse the grounds away.
The grounds calm and tighten the skin giving you a fresh look. Just be careful that you don’t get coffee grounds in your eyes with this hack! To better keep the grounds in place (and add even more skin reviving properties) mix the coffee grounds with a bit of honey.
What to Do with Coffee Grounds When Backpacking
If you are planning a backpacking trip, you’ll want to think through the best way to travel with coffee on the trail. You want your coffee paraphernalia to be lightweight and your grounds to stay fresh. By planning ahead, you can make sure you have everything you need for a fresh cuppa while you are exploring the great outdoors.
Pack It In
When you pack coffee grounds, you want to keep them fresh-tasting, and moisture-free. Also, you want a fairly compact way to store your grounds. Bulky Tupperware containers may take up too much room in your backpack. So, we checked into other ways to pack up your grounds to take them on the trail. The best option we found was aluminum foil resealable bags.
With these aluminum ziplock-style bags, you can measure your grounds while you still have your scale or measuring spoons close by. Then portion your grounds accordingly into the bags. This is a lightweight, waterproof way to carry your grounds into a campsite.
Brew a Cuppa
There are several different ways to make coffee at a campsite. You can use a campfire-friendly percolator. Or, if you want something more lightweight but durable, you can bring along a collapsible pour-over filter or pack an Aeropress. These two types of coffee makers are pretty easy to carry around and are durable enough to “rough it” with you.
If you don’t want to take the trouble to pack in grounds and carry around coffee makers, you can always opt for instant coffee on the trail. This quick brew method is pretty low maintenance. The granules dissolve in your cup, which means you don’t have to worry about packing your grounds out.
Pack It Out
The USDA advises that coffee grounds should be “packed out” and disposed of with the rest of your trash. This is part of the “leave no trace behind” mantra that campers are expected to adhere to.
Not only do you want to keep the campsite clean for other campers, but packing out your grounds could also ensure your safety. While pests and cats hate the smell of coffee, apparently bears find the smell of coffee grounds attractive. No one wants these furry friends lumbering through their camp at night!
Play it safe and store your grounds with the rest of your trash in sealed containers. Throwing them on the campfire or outside your tent door could potentially lead to disastrous results.
What not do with coffee grounds
While coffee grounds have a lot of great uses, they have their limits, too. We’ve covered a lot of ways you can use your grounds. Here are a few ways you shouldn’t use them.
Don’t run coffee grounds down the garbage disposal.
You may have heard that dumping your coffee grounds down a garbage disposal is ok, however, most plumbers will beg you not to.
Coffee grounds are good at eliminating foul odors and shouldn’t hurt your garbage disposal system in small amounts. However, a daily dose of coffee grounds down your sink can do more harm than good by clogging up your drains and pipes.
Don’t sprinkle coffee grounds on tomatoes, clover, or alfalfa.
These plants are more sensitive and don’t appreciate a direct dose of used coffee grounds. However, if you add coffee grounds to a compost pile (and keep the proper brown to green ratio), these plants should happily accept the mulch.
Don’t allow your dog to ingest coffee grounds.
Even moderate amounts of coffee or coffee grounds can be dangerous or even deadly for dogs. This means that if your dog is the curious type, throwing coffee grounds directly into your flower bed should probably be avoided. If your pup ingests the grounds, he may need an immediate trip to the vet.
Don’t reuse your coffee grounds to make coffee.
Nothing bad will happen, it just won’t taste good. Most of the flavor is extracted when you brew coffee the first time around. So, if you reuse your grounds, you will be left with mostly undesirable bean flavors. Your cuppa will taste weak, bitter, and sour.
Life is too short to drink bad-tasting coffee! Use those grounds to make a coffee candle, and don’t look back.
FAQs
How long do coffee grounds stay fresh after they are ground?
Grinding right before you brew will ensure you have the freshest flavor. However, if you are relying on your local coffee shop to grind your beans, it is best to use your coffee within one week after grinding, or two weeks max.
Can I find spent coffee grounds at Starbucks?
Yes! Many Starbucks stores give out free used coffee grounds on a first-come, first-serve basis. On average, Starbucks serves coffee to over one million Americans every day. This means you have a good chance of finding extra coffee grounds to use in your garden or however you choose!
If I grind coffee too fine, can I fix it?
Luckily, yes, you can “fix” ground coffee that is too fine. If you are using a french press brew method, put the fine grind on the bottom and top it off with a coarser grind. This layering should keep most of the fine grounds from rising through your mesh. You can also strain your coffee to keep any wayward grounds out of your coffee.
Keep in mind, though, that fine grounds will over-extract quicker than coarse grounds so, you may want to adjust your brew time accordingly. Or, you can just regrind your beans and use the fresh fine grinds for a body scrub.
Wrap Up
Coffee is my favorite bean for several reasons. Not only does a fresh cuppa taste great going down, but even after your coffee is gone, the used grounds are still useful. You can keep your garden green, get rid of weeds, tenderize meat, keep mosquitos away, and keep your locks looking luscious. The more we learn about coffee, the more we love it.