What to do with your coffee grounds?

What are coffee grounds?

Coffee grounds are the solid, granular residue left behind after brewing coffee at home. If you use a coffee machine, spent coffee grounds get compacted into cakes. Looking for an easy, consistent way to brew at home? Our Kottea Oslo review is a good place to start.

Thanks to their caffeine and phenolic compounds, coffee grounds have antioxidant, anti-inflammatory, and antiviral properties that make them genuinely useful for skin and hair, with caffeine boosting blood flow for a firmer, more radiant appearance. Environmentally, recycling spent coffee grounds reduces waste and limits chemical use around the home.

Using your coffee grounds in the garden and soil

Coffee grounds as a compost activator

Many of you compost coffee leftovers after grinding them with your peelings. But did you know coffee grounds also make an excellent compost activator? Earthworms are particularly fond of them.

Sensitive to caffeine, earthworms become more active in transforming organic matter into rich compost, whether you’re tending a full compost pile or a small worm bin. Add your coffee grounds to the mix; they act as a soil improver when combined with other organic material, helping aerate heavy soils and improve drainage. That said, grounds alone aren’t a balanced fertiliser: treat them as a nitrogen-rich supplement, not a standalone feed.

Getting the compost balance right: Coffee grounds are a nitrogen-rich “green” material, so they shouldn’t go into your compost bin on their own. Balance every load of grounds with roughly three parts carbon-rich “brown” material, such as dried leaves, straw or shredded cardboard, and paper filters if you use a filter machine. This balance is what turns kitchen waste into a genuine soil improver rather than a soggy, smelly heap. As a general process, mix fresh coffee grounds through the pile rather than dumping them in a single wet layer, which slows decomposition.

Coffee grounds as plant food and fertiliser

Used coffee grounds make a great garden fertiliser for acid-loving plants. They contain around 1–2% nitrogen by weight, plus phosphorus, potassium, and trace minerals like magnesium and calcium, acting as a genuine slow-release plant food.

One note on acidity: after brewing, used grounds sit at a nearly neutral pH of 6.5–6.8. They won’t dramatically acidify your soil, but their nutrients still benefit acid-loving plants when applied correctly.

Application tips:

• Mix into soil rather than piling on the surface, since dry grounds can form a water-repelling crust
• Keep grounds to a maximum of 20% of your compost mix
• Apply outdoors once a month, or every two months for indoor plants

Coffee grounds for your lawn, roses and deterring slugs

Coffee grounds double as a natural pest deterrent against slugs, snails, caterpillars, ants, mosquitoes and fleas. Scatter a light layer across your lawn to feed the grass while discouraging pests, and work some into rose beds for an extra nutrient boost.

Burning coffee grounds to repel mosquitoes

To repel mosquitoes, burn a cup of dried grounds in a container; the smoke smell drives them away.

How to reuse coffee grounds as a beauty product

Coffee grounds offer a natural, chemical-free alternative to commercial beauty products, with benefits for both skin and hair.

Coffee grounds as an exfoliating body scrub

The coarse texture of coffee grounds makes them an excellent natural exfoliant for your face and body. Thanks to the caffeine they contain, they cleanse deep down, sloughing off dead skin and leaving a rejuvenating effect. The gentle scrubbing action also helps reduce the appearance of cellulite by stimulating blood circulation.

Mix your used grounds with a carrier oil like olive oil or coconut oil, or try honey for added moisture (a few drops of an essential oil, such as lavender, add a pleasant scent). Massage the mixture onto damp skin in circular motions, then rinse thoroughly. Pores are unclogged and skin feels tighter almost instantly. This simple exfoliating scrub earns a permanent spot in your skincare routine, replacing several store-bought products while cutting the risk of allergic reactions to chemical ingredients.

Coffee grounds for hair growth and colour

Coffee grounds promote hair growth and soothe itchy scalps while caring for oily hair. Simply apply as a conditioner to wet hair, massage into your scalp, and rinse. The grounds exfoliate the scalp and stimulate blood circulation, boosting growth.

Their rich brown colour hints at their dyeing power. Used on brown and dark hair, coffee grounds revive colour, restore shine, and naturally camouflage grey hair, slowing its appearance over time.

Recycling coffee grounds as a household product

It’s hard to believe, but it’s true: coffee grounds make a surprisingly effective cleaning product, as our team discovered.

A super deodoriser

Coffee grounds work as a natural odour neutralizer, lifting stubborn garlic, onion, or fish smells from hands or fridges. Fill a small bowl with used grounds to absorb odours without leaving a coffee scent, and refresh every two weeks.

Drain maintenance

Leftover coffee also helps prevent clogs and odours, saving you from pricey drain cleaners. Tip a tablespoon of grounds into your sink, run hot water for two minutes, and repeat weekly to keep grease at bay.

Coffee grounds to polish and clean furniture

Wet coffee grounds buff out fine scratches on wooden furniture: mix in a pinch of salt for extra grit, then rub gently with a cloth. They also work as an abrasive cleaner for greasy stovetops.

Coffee grounds as a natural dye

Coffee grounds also double as a natural fabric dye: soak clothing in a mixture of grounds and water, then let it dry for a unique, earthy tone. If the cups of coffee you brew daily leave plenty of grounds to spare, it’s worth putting them all to good use rather than sending them to landfill.

Can you grow mushrooms with coffee grounds?

Used coffee grounds are a genuine growing medium for gourmet mushrooms, such as oyster mushrooms. Because they’ve already been through the brewing process, coffee grounds are naturally sterilised, which saves you the usual step of pasteurising straw or sawdust.

1. Mix fresh (still slightly warm) coffee grounds with mushroom spawn in a breathable growing bag.
2. Seal the bag and incubate it in the dark at around 20–24°C for two to three weeks.
3. Once the bag turns white with mycelium, cut small holes and move it to a cooler, humid spot with indirect light.
4. Harvest your first mushrooms within a couple of weeks.

It’s a fun, low-cost way to give your grounds a genuine second life instead of the bin — and a great beginner project if you’re curious about home mushroom growing.

Coffee grounds as a dry rub for meat

Used coffee grounds aren’t just for the garden and the bathroom — they also work in the kitchen. Combined with salt, the natural acids and enzymes in coffee help tenderise red meat such as steak or brisket, while adding a rich, earthy crust when the meat is seared.

Simple dry rub recipe:

• 2 tbsp used or fresh coffee grounds
• 1 tbsp salt
• 1 tsp smoked paprika
• ½ tsp garlic powder and onion powder
• A pinch of chilli or ground coriander to taste

Rub the mixture generously over the meat before cooking, and leave to rest for a few hours between applications and cooking for the best flavour.

Where to get coffee grounds if you don’t brew at home

Don’t drink enough coffee to fill your compost bin? You don’t need your own machine to enjoy the benefits. Many coffee shops and cafés set aside used grounds for customers to take home for free — it’s always worth asking at the counter. Friends, family or neighbours who brew daily (including with instant coffee, though this leaves far less residue) are another easy source. A quick weekly collection is often enough to keep a small compost bin or a few garden beds topped up.

Frequently asked questions about used coffee grounds

Which plants do not like used coffee grounds?

Some plants dislike the acidity in coffee grounds, including lavender, geraniums, asparagus ferns and rosemary, which prefer neutral to alkaline soil. Gardeners should test soil pH before adding grounds near seedlings or delicate containers.

How to store used coffee grounds?

Spread used grounds thinly on a tray and let them air-dry, then store in an airtight jar or plastic tub. Stored this way, they’ll stay usable for several weeks without developing mould.

What animals will coffee grounds keep away?

Used coffee grounds naturally deter garden pests: cats avoid sprinkled areas, slugs and snails dislike the gritty texture and caffeine, and the scent repels ants. It’s a handy, chemical-free first line of defence.

Can I just sprinkle used coffee grounds in my garden?

Yes, sprinkling a light layer around plants works, though mixing grounds into soil gives better results and avoids a water-repelling crust. Use a thin layer and refresh it monthly.

How to dispose of coffee grounds?

The best way to dispose of coffee grounds is to reuse them: dry and store them, add them to your compost heap or wormery, or dig them into garden soil. Avoid pouring large amounts down the drain, as this can contribute to clogs over time.

Are coffee grounds good for the garden?

Yes, in moderation — they enrich compost and soil with nitrogen, phosphorus and potassium, but they’re not a standalone fertiliser and should be mixed in rather than piled on the surface.

What to do with unused coffee grounds?

Dry them fully and store them in an airtight container; they’ll keep for several weeks and can then be used in compost, the garden, or as a household deodoriser.

How to reuse coffee grounds for skin?

Mix used, cooled grounds with a carrier oil or honey to make a gentle exfoliating scrub — massage onto damp skin, then rinse thoroughly.

How to make coffee with grounds without a machine?

You can steep coarse grounds in hot water for a few minutes then strain (a simple “cowboy coffee” method), or use a French press if you have one — no electric machine required.

Do tomato plants like coffee grounds? Busting a common myth

No — despite popular garden advice, tomato plants don’t like coffee grounds. Residual caffeine can inhibit their growth and germination, so it’s best kept out of tomato beds and seed trays entirely.

From compost and acid-loving plants to body scrubs, dry rubs and homegrown mushrooms, your spent coffee grounds have far more to offer than a trip to the bin. Start small — a bowl in the fridge, a sprinkle in the compost heap — and you’ll quickly find the uses that fit your own kitchen and garden. At MaxiCoffee, we like to think good coffee deserves a good second life too.