We’d hazard a guess that you’ve had at least one cup of coffee today, be it from a reusable cup on your way to work, on a mid-morning break, at your desk while you work, or maybe you’re sipping while you read this. Coffee break, coffee catch up, coffee and a walk—the modern world is obsessed with caffeinating.
As one of the world’s most consumed beverages and traded commodities, the impact of the coffee industry should be scrutinized. While the rise of fair trade coffee brands tell us more people are clueing into its social problems, what about environmental ones?
Did you know that a double espresso shot uses 18 grams of ground coffee? When you consider that, globally, an estimated 2.25 billion cups of coffee are consumed every day, that is a whole lot of coffee grounds—44,643 tons to be exact.
So, what to do with coffee grounds that have satisfied our caffeine fix—but won’t cause the planet to crash? Can you reuse coffee grounds? You bet your beans, you can!
Contents: Uses For Used Coffee Grounds
- Compost Coffee Grounds Jump to section
- Exfoliate Skin Jump to section
- Heat Your Home Jump to section
- Grow Gourmet Mushrooms Jump to section
- Use As A Raw Fertilizer & Pesticide Jump to section
- Touch Up Wooden Furniture Scratches Jump to section
- Absorb Strong Odors Jump to section
- Remove Fleas From Pets Jump to section
- Make A Natural Cleaning Scrub Jump to section
- Stimulate Hair Growth Jump to section
- Add Into Concrete Jump to section
Compost Coffee Grounds
We’re sure you’re familiar with composting—the process of turning organic items such as food scraps into compost for the garden—but did you know that used coffee grounds are a great addition to your compost bin?
Containing nitrogen that helps organic materials break down into nutrient-rich fertilizer, studies have found that compost made with coffee grounds and kitchen waste was richer in nutrients, produced fewer greenhouse gas emissions, and yielded overall better quality compost.
This is also the easier answer for what to do with old coffee grounds.
Exfoliate Skin
Coffee grounds make a great exfoliating agent in zero waste skin care. Since they do not dissolve in water, the course grounds are perfect for scrubbing away dirt and dead skin cells.
Mix coffee grounds with a little bit of water or coconut oil and sugar, and scrub them with your hands directly onto your face and body. Coffee grounds can also be mixed with a small amount of honey and used as an exfoliating lip scrub.
Coffee ground uses go beyond exfoliation, too. Research suggests the caffeine in coffee grounds has potent antioxidant properties that helps protect the skin from sun damage and boosts collagen levels to reduce premature aging. It can also increase blood flow, which aids in overall skin health.
Heat Your Home
If you have a wood stove, coffee grounds can be turned into pellets and used as fuel. You’re already doing good by heating your home with a wood stove rather than fossil fuels that produce a lot of pollution, but adding coffee into the mix takes your green credentials even further.
Pellets are usually made from compressed sawdust, but coffee is said to make them more efficient since coffee grounds have a higher caloric value than ordinary pellets. They contain 25% more energy and, therefore, emit more heat in a shorter amount of time, saving fuel and decreasing CO2 emissions. Even better, they give off a delightful aroma as they burn.
So save up your grounds and make your own pellets.
Grow Gourmet Mushrooms
Ever considered adding mushrooms to your apartment garden?
Growing gourmet Oyster mushrooms might not be the first thing that comes to mind when you think of what to do with used coffee grounds, but research shows there are a whole load of benefits to using coffee grounds in mushroom growing processes.
Mainly, the benefit of removing the need to sterilize the surface on which the mushroom grows as the grounds will have already been sterilized in the coffee brewing process. Here’s how:
- Mix the mushrooms with straw in sealed bags and incubate the bags in the dark at 20-24 degrees celsius for 2-3 weeks
- Add holes to the bags and place in a shaded spot with some indirect light and spray with water each day
- After about a week, mushrooms will grow. Once they reach a good size and the top of the caps begin to flatten out, they are ready to harvest.
Use As A Raw Fertilizer & Pesticide
Wave goodbye to soil depleting and ecosystem-destroying fertilizers and use up your French Press leftovers instead, adding them directly to soil. Coffee grounds are rich in nutrients, especially nitrogen—a major component of chlorophyll, the compound by which plants use sunlight energy to produce sugars from water and carbon dioxide (i.e. photosynthesis).
They also hold other nutrients like potassium (increases root growth and improves drought resistance) and phosphorus (essential for cell division and the development of the growing tip of the plant).
The grainy texture of coffee grounds can also deter slugs and snails from getting to your flowers and plants, making them excellent organic pesticides for your sustainable garden.
Cats don’t like the strong smell of coffee grounds either, so sprinkling them around your garden or driveway can stop them from spraying, providing a kind, chemical-free way of deterring them.
Touch Up Wooden Furniture Scratches
We may use coffee to cope with our mistakes, but in some cases—like that of wooden furniture—it can actually fix them. Due to the natural dark dye in coffee and the mildly abrasive texture of the grounds, they can be used to touch up marks on brown wood.
Mix a small amount of old coffee grounds with warm water to make a paste, rub the paste over the scratch, and wipe it off 5-10 minutes later. The grounds will re-stain the wood, making scratches less noticeable. Who wood have thought?
Absorb Strong Odors
Put a bitter end to harsh smells by using your extremely absorbent coffee grounds as a natural air freshener and deodorizer. Scientists at The City College of New York developing an eco-friendly filter to remove toxic gasses from the air found uses for old coffee grounds in absorbing sulfur.
Even if you don’t struggle with sulphur’s notorious stench of rotton eggs, you can use it to cover up plenty of other bad smells with a breath of fresh beans instead.
Spread a thin layer of wet coffee grounds on a baking sheet once you’ve had your morning cup of Joe, and place them in a 250 degree oven until dry. Store them in an open jar and place them anywhere you wish to eliminate bad smells—kitchen cabinets, refrigerators, the toilet, or next to a litter box are all usual suspects.
Remove Fleas From Pets
There are many products on the market for treating fleas, but many of them contain harsh chemicals that produce unwanted side effects.
Fortunately, fleas don’t seem to like coffee and it can be used as a natural treatment for fleas—takign your zero waste dog to the next level. Simply rub the grounds throughout your pet’s fur after shampooing, rinse them off, and allow them to dry as usual.
Beware, though, coffee grounds should only be used externally on pets as they can be toxic if consumed, by dogs especially.
Make A Natural Cleaning Scrub
Many traditional cleaning products use volatile organic compounds (VOC). Not only are these hazardous for human health and environments, they also end up in the ozone layer, which is one of the main drivers of climate change.
In their place, used coffee grounds are the ultimate non-toxic cleaner. They are abrasive and their coarse texture can help remove build up on hard-to-clean surfaces (like stovetops) and cookware. They may even sanitize due to their antibacterial and antiviral properties.
Sprinkle the grounds directly onto the surface or object you are cleaning and scrub as usual. Make sure to rinse thoroughly afterward; as much as we love the stuff, you don’t want bits of coffee ending up in your food.
Stimulate Hair Growth
Regardless of the goodness that their marketing promises, shampoos, conditioners and styling products often leave residue behind that can dull and weigh down your hair (but psst…switching to natural shampoo can also help!).
But when you need a little extra root boost, you’ll find coffee grounds good for that, too. Exfoliating your scalp with coffee grounds can help remove buildup and dead skin cells, and some studies suggestcaffeine stimulates human hair growth.
Before you shampoo, simply grab a handful of coffee grounds and massage them into your scalp and hair for a few minutes. Then wash and rinse as you normally would. Do this one to two times per week, or as needed.
Add Into Concrete
What do coffee and concrete have in common? They give us strength to withstand the storms that come our way!
Researchers from Australia’s mecca of cafe culture, Melbourne, have found that you can transform your spent coffee grounds into a valuable resource. Studies from the Royal Melbourne Institute of Technology have found concrete can be made 30% stronger by replacing a percentage of sand with spent coffee grounds, contributing to a greener approach to construction.
Reusing coffee grounds in concrete not only saves space in landfill but also preserves finite natural resources (such as sand), so you can do your bit to build a better world.