Ten ways to re-purpose leftover coffee, according to experts

From creating a DIY air freshener to boosting plant fertiliser, these creative ways to reuse leftover coffee will help you reduce waste at home. 

Experts at UK-based business Coffee-Direct.co.uk have shared 10 ideas using the whole beans, coffee grounds and even a cold cup of coffee.  

Coffee can be used on your hair as a leave-in condition, or even as a remedy for bad breath. In the home, it also can be re-purposed as a DIY air freshener, and can be incorporated in your food as a syrup or even a marinade as well. 

Scroll down to find out more in detail about creative ways to repurpose your coffee.  

Experts at UK-based business Coffee-Direct.co.uk have come up with ten eco-friendly ways to re-use old coffee so you don’t have to throw it out (pictured: coffee beans and ground coffee)

1. Wood Stain

As well as being a natural, non-flammable alternative to store-bought wood stains, staining with coffee will give the wood a beautiful, caramel tone. 

Coffee reacts with the tannins in wood to help reduce blotchiness and give the wood a uniform colour. Simply wait for your brewed coffee to cool, sand down your surface and use a rag to evenly coat the wood. The darker you want the stain, the more coffee you use!

2. Natural Pest Repellent

The smell of coffee is great for repelling common household pests such as mosquitos, ants, slugs, cockroaches and more. 

All you have to do is set bowls of coffee grounds out, and this should keep the pests away. We recommend freshly ground coffee for this, as the aromas will linger longer. 

3. Coffee syrup 

Why not use your leftover coffee to upgrade your next coffee? Use coffee syrup to drizzle over your next coffee frappé! Simply boil brewed, black coffee with an equal amount of sugar until it becomes reduced and thick in texture. 

This syrup can last in the fridge for two weeks, so you can also use this to upgrade desserts such as ice-cream and pancakes too.

You can also put some of these coffee grounds in your pet shampoo to help naturally prevent fleas.

4. Leave- In Conditioner

Caffeine in coffee is great for hair. Not only does it encourage the hair roots to grow, but it stimulates the roots and improves scalp health too. 

After shampooing your hair, simply pour cold coffee over your head and scalp. So that the coffee doesn’t stain your bathtub, make sure you do this over a bucket. 

Put your hair in a shower cap and leave the coffee in for half an hour before rinsing off with warm water. 

Do this once a week, and you will notice an improvement in the thickness and texture of your hair.

5. Indoor Décor

Old or leftover coffee beans make rustic and beautiful vase fillers for the home. Gather light and dark variations of coffee beans in clear glass vases, checking if they have a nice scent when combined. 

Arrange your flowers in the vases, and you will find that the coffee beans hold the stem upright. If you do not have enough coffee beans to fill the vase, you could try layering them with other small stones, dried petals or glass beads for visual interest.

6. Marinade

Few people know that with the right spices, brewed coffee can provide a pleasant and delicate taste to steak, pork or fish. 

Sauté one medium onion and four minced garlic gloves and add it to a bowl. To this, add 240ml strong coffee, 60ml balsamic vinegar, 55g of brown sugar, 60ml Dijon mustard, 3 tbsp olive oil, pepper and salt to taste. 

Cover your fish or meat in the marinade and leave it in the fridge for at least an hour before cooking.

7. Plant Fertiliser

Diluted coffee can be extremely beneficial to plant health. As brewed, black coffee contains potassium and magnesium, it acts as a nutrient to plants allowing for stronger stems and a vibrant, green growth. Stock image

Diluted coffee can be extremely beneficial to plant health. As brewed, black coffee contains potassium and magnesium, it acts as a nutrient to plants allowing for stronger stems and a vibrant, green growth. Stock image

Diluted coffee can be extremely beneficial to plant health. As brewed, black coffee contains potassium and magnesium, it acts as a nutrient to plants allowing for stronger stems and a vibrant, green growth. 

To use this as fertiliser, dilute your brewed black coffee so that it is a 1: 4 ratio (coffee: water) and feed your plants once a week with this solution. Make sure there is no sweetener that could attract pests, and that your coffee is not too strong when ‘watering’ your plants, as it could be too acidic for the soil.

8. DIY Air Freshener

Coffee is fantastic for neutralising other odours, which is why it makes a great DIY air freshener. Simply place some coffee beans in a mesh bag and stash it away under the passenger seat. The coffee’s natural scent will be released slowly, and the beans will absorb any unpleasant, overpowering odours.

9. Ice Cubes

If you don’t want to water down your iced coffee, pour your leftover brew into an ice cube tray. Freeze the cubes, and then pop them out whenever you need to make your iced drink extra cold and flavourful. 

Depending on your coffee flavour, you can also add or adjust the ingredients in your ice cubes to upgrade your drink. 

For example, you can whisk together sweetened condensed milk and leftover coffee for a Vietnamese coffee variation, or add some caramel to your leftover coffee before freezing for a Macchiato variation.

10. Eliminate bad breath

While those old coffee beans may not be good enough to make coffee with, they may still be edible. Some may attribute their bad breath to drinking coffee, but it is actually the caffeine to blame – not the bean. 

Believe it or not, sucking on a coffee bean can help eliminate bad breath. As well as being much cheaper than a breath mint, it also tastes great and neutralises even the strongest scents such as garlic.