What To Do With Used Coffee Grounds?

You'll be surprised how useful spent coffee grounds can be. Here's what to do with your old, unused, or spent coffee grounds before throwing them in the trash.

June 21, 2024
Coffee beans and grounds stored in a metal tin to be used for other purposes.

While we’re adamant about not using them to make another cup of coffee, there are many other ways to reuse your spent grounds — in the garden, as cleaning products, and even for a bit of self-care — just to name a few. 

We’re going to dive into all the best ways to use your leftover coffee grounds, encouraging sustainability and helping you save money along the way — who doesn’t love that?

6 Creative Ways to Reuse Coffee Grounds

This list isn't conclusive, but it should get your creative juices going and provide a good overview of just how useful coffee grounds can be with a little imagination.

1. Garden Fertilizer

One of the best things to do with leftover coffee grounds is to use them in the garden as a fertilizer. Coffee grounds have an impressive nutritional profile, offering trace minerals like potassium as well as nitrogen [1]. Save up your grounds and put your green thumb to the test. 

To use, simply mix a few scoops of coffee into the soil. For potted plants, you can sprinkle it around the top as a top dressing — as you water your plants, the nutrients of the coffee will slowly infuse into the soil where your plants can use them.

You can also add spent coffee to your composter to speed up the process and enrich the compost’s nutrient content [2].

Related: How to Grind Whole Coffee Beans

2. Cleaning Products

If you don’t have a garden or don’t fancy yourself as a gardener, there are plenty of ways to use leftover coffee grounds in the home. It’s very versatile in household cleaning and maintenance. 

You can leave those expensive cleaning products at the store and make your own natural, affordable products using the coffee grounds.

  • Natural Deodorizer — The coffee grounds neutralize odor in your fridge or car.
  • Abrasive Cleaner — The texture of the grounds helps to clean hard surfaces without harsh chemicals.
  • Furniture Scratch Repair — You can mask scratches on wooden furniture with a paste made from coffee grounds.

3. Hair & Skin Care

One of our favorite ways to use up your coffee grounds is to make beauty products. Coffee grounds are great for skin and hair care, and it’s an awesome way to save money. They’re entirely natural, so making personal care products out of coffee grounds is super sustainable and good for your skin!

There are a few ways that you can use coffee grounds in your beauty routine:

  • Skin Exfoliation — You can use coffee grounds as a natural scrub to remove dead skin cells.
  • Hair Care — Coffee grounds enhance hair texture and promote scalp health [3].
  • Reduce Appearance of Cellulite — Caffeine in coffee grounds may help minimize cellulite when applied to the skin, improving blood flow [4].

4. Creative Crafts

Looking for some wholesome entertainment or want to get into a new hobby without spending a fortune? 

It’s actually really easy to get crafty with coffee grounds, and there are a few different ways to use them:

  • Natural Dye & Paints — You can use leftover coffee grounds to dye fabric or paper.
  • Homemade Candles — Add a coffee scent to homemade candles for a cozy ambiance and a warming vibe.

5. Culinary Uses

Even though you can’t really use coffee grounds twice to make another brew, you can use them in the kitchen. There’s still plenty of flavor in the grounds — just not enough for another cup of coffee. 

This is a fun way to experiment with different kinds of coffee. Try using everything from intense dark roasts, like our HaNoi robusta to lighter, fruitier beans, such as our DaLat arabica beans, or blends like SaiGon OG. 

Here are a couple of ways to use coffee grounds in the kitchen:

  • Meat Tenderizer — The acidic nature of the coffee grounds helps tenderize and flavor meats.
  • Flavor Enhancer — Coffee grounds add a unique flavor to baked goods or marinades.

Related: Difference Between Arabica and Robusta

6. Bug Repellent

Some of coffee’s compounds (including caffeine) deter pests like mosquitos, wasps, ants, slugs, and others. 

Sprinkle a 2-inch line around plants, doorways, or even directly on top of an ant hill. 

To keep mosquitos at bay while camping, toss some grounds onto the smoldering fire; the smoke does a great job at repelling pesky mozzies.

You can also use it as a top dressing for plants to fight back against bugs that lay their eggs in the soil, such as thrips or fungus gnats.

FAQs: Using Coffee Grounds

Now that you know all about reusing your leftover coffee grounds around the home and your garden, let’s round things out with some frequently asked questions. 

Related: 105 Coffee Facts on History, Health, & Trivia

1. Can coffee grounds be reused for brewing?

You shouldn’t really reuse coffee grounds for brewing. The second time around will result in a bad, bitter taste and tends to be a lot weaker overall.

2. Are coffee grounds safe for all plants? 

Coffee grounds are great for some plants but not for all. They are beneficial for acid-loving plants but should be used sparingly for others. If you're not sure about your specific plant, check online before using the coffee-enriched fertilizer.

3. How should I store used coffee grounds?

To store the used coffee grounds, you’ll need to dry them first, then store them in an airtight container. If they have moisture in them, they’ll go moldy and be rendered useless. 

4. Can coffee grounds clog drains?

Yes, coffee grounds can clog drains. You need to avoid disposing of them down the sink or toilet; otherwise, you'll have issues with your pipes later on. 

5. Are coffee grounds pet-safe?

Coffee grounds aren’t safe for pets as a foodstuff. However, while they should not be consumed by pets, you can use coffee grounds on their fur for things like flea removal.

6. How often should coffee grounds be replaced as a deodorizer?

If you’re using coffee grounds as a deodorizer, you should replace them every two weeks or when their effectiveness diminishes. Make sure you have a batch of coffee grounds either drying out or in airtight storage to replace them over time. 

7. Can I use coffee grounds on my face?

Yes, you can use coffee grounds on your face, but make sure to mix them with oil or water to create a gentle scrub. This helps to exfoliate your skin, so wash your face first, apply the scrub, and then rinse everything off with warm water.

8. What is the best way to compost coffee grounds? 

The best way to compost coffee grounds is to mix them with a variety of compost materials to balance the nitrogen content. This can include all kinds of food waste that can help you create a sustainable garbage cycle!

9. Do coffee grounds deter all types of insects?

Coffee grounds don’t deter all types of insects, but they are particularly effective against ants and slugs. As such, they’re great for use on the floor in the garden and on patios in the summer months. 

10. Can coffee grounds be used to clean all types of surfaces?

Coffee grounds can't be used to clean all types of surfaces. The best thing to do is to test them on a small area first, as they may stain porous materials.

References

  1. Nuhu A. A. (2014). Bioactive micronutrients in coffee: recent analytical approaches for characterization and quantification. ISRN nutrition, 2014, 384230. https://doi.org/10.1155/2014/384230
  2. Adi, A. J., & Noor, Z. M. (2009). Waste recycling: utilization of coffee grounds and kitchen waste in vermicomposting. Bioresource Technology, 100(2), 1027–1030. https://doi.org/10.1016/j.biortech.2008.07.024
  3. Herman, A., & Herman, A. P. (2013). Caffeine's mechanisms of action and its cosmetic use. Skin pharmacology and physiology, 26(1), 8–14. https://doi.org/10.1159/000343174
  4. Herman, A., & Herman, A. P. (2013). Caffeine's mechanisms of action and its cosmetic use. Skin pharmacology and physiology, 26(1), 8–14. https://doi.org/10.1159/000343174