Beyond the Brew: Ingenious Household Uses for Spent Coffee Grounds and Tea Leaves

Question: How can I repurpose used coffee grounds or tea leaves for practical household uses?

The fragrant aroma of morning coffee and the comforting warmth of steeped tea are beloved rituals for many. Yet, after the final sip or brew, we’re often left with a mound of used coffee grounds or tea leaves. Instead of sending these organic materials to the landfill, consider their potential for ingenious household reuse.

Gardening Goldmine

Spent coffee grounds are a fantastic addition to the garden, acting as a natural fertilizer and pest deterrent. Rich in nitrogen, they can boost the growth of leafy greens, tomatoes, and root vegetables [2]. The grounds also contribute to soil structure, improving drainage and aeration. For gardeners seeking to deter common pests like slugs and snails, a barrier of dried coffee grounds around vulnerable plants can be surprisingly effective. Similarly, used tea leaves, particularly black tea, can be beneficial. They contain tannins which can slightly acidify the soil, making them suitable for acid-loving plants like blueberries and rhododendrons. They also add organic matter to the soil, improving its fertility and moisture retention.

Enhancing Compost and Soil Health

Both coffee grounds and tea leaves are excellent ‘green’ materials for your compost bin. Their inclusion introduces valuable nitrogen, accelerating the decomposition process and creating a richer, more nutrient-dense compost. When added to the soil, they slowly release nutrients as they break down, acting as a slow-release fertilizer. Studies have explored the use of spent coffee grounds in biocomposites, demonstrating their potential as a component in materials that can influence plant growth positively [2]. This highlights their inherent value in promoting a healthy soil ecosystem.

Natural Cleaners and Deodorizers

The slightly abrasive texture of coffee grounds makes them a surprisingly effective natural cleaning agent. A small amount of used grounds can be used to scrub stubborn grime from pots and pans, offering an eco-friendly alternative to harsh chemical cleaners. Be mindful of porous surfaces, however, as coffee can potentially stain. For odor elimination, coffee grounds are unparalleled. Place a small open container of dried grounds in your refrigerator to absorb lingering food smells. They can also be used to neutralize odors in garbage disposals or even on your hands after chopping garlic or onions. Used tea leaves, especially those with strong aromas like Earl Grey, can also help freshen spaces. Dried leaves can be placed in small sachets and tucked into drawers or closets for a subtle, pleasant scent.

Beyond the Basics: Creative Applications

Research has begun to explore the valuable compounds within coffee grounds. For instance, spent coffee grounds have been identified as a source of chlorogenic acid, a compound with various potential applications [8]. Furthermore, methods are being developed for the simultaneous extraction of caffeic acid and the production of cellulose microfibrils from coffee grounds using techniques like hydrodynamic cavitation [7]. While these are more advanced scientific explorations, they underscore the inherent chemical richness of these discarded materials. The complex volatile compounds within coffee [3, 6] and the flavor profiles of coffee co-products [4, 5] also hint at their potential beyond simple waste. Even the foam of espresso, rich in proteins and lipids [1], is a testament to the complex biological structures found within coffee. These findings suggest that even more sophisticated uses for these materials may emerge in the future.

Repurposing used coffee grounds and tea leaves is a simple yet impactful way to reduce waste and harness the natural benefits of these everyday kitchen staples. From enriching your garden and purifying your home to potentially contributing to future material innovations, these humble byproducts offer a wealth of practical applications waiting to be discovered.

References

[1] — Ernesto Illy, Luciano Navarini — Neglected Food Bubbles: The Espresso Coffee Foam. — 2011-Sep — https://pubmed.ncbi.nlm.nih.gov/21892345/ [2] — Magdalena Zdanowicz, Marta Rokosa, Magdalena Pieczykolan, Adrian Krzysztof Antosik, Katarzyna Skórczewska — Biocomposites Based on Wheat Flour with Urea-Based Eutectic Plasticizer and Spent Coffee Grounds: Preparation, Physicochemical Characterization, and Study of Their Influence on Plant Growth. — 2024-Mar-06 — https://pubmed.ncbi.nlm.nih.gov/38473683/ [3] — Gustavo Galarza, Jorge G Figueroa — Volatile Compound Characterization of Coffee ( — 2022-Mar-21 — https://pubmed.ncbi.nlm.nih.gov/35335365/ [4] — Katarína Poláková, Alica Bobková, Alžbeta Demianová, Marek Bobko, Judita Lidiková, Lukáš Jurčaga, Ľubomír Belej, Andrea Mesárošová, Melina Korčok, Tomáš Tóth — Quality Attributes and Sensory Acceptance of Different Botanical Coffee Co-Products. — 2023-Jul-11 — https://pubmed.ncbi.nlm.nih.gov/37509767/ [5] — Rongsuo Hu, Fei Xu, Liyan Zhao, Wenjiang Dong, Xingyuan Xiao, Xiao Chen — Comparative Evaluation of Flavor and Sensory Quality of Coffee Pulp Wines. — 2024-Jun-27 — https://pubmed.ncbi.nlm.nih.gov/38999011/ [6] — Faguang Hu, Haohao Yu, Xingfei Fu, Zhongxian Li, Wenjiang Dong, Guiping Li, Yanan Li, Yaqi Li, Bingqing Qu, Xiaofei Bi — Characterization of volatile compounds and microbial diversity of Arabica coffee in honey processing method based on different mucilage retention treatments. — 2025-Jan — https://pubmed.ncbi.nlm.nih.gov/39974542/ [7] — Hitoshi Soyama, Kousuke Hiromori, Naomi Shibasaki-Kitakawa — Simultaneous extraction of caffeic acid and production of cellulose microfibrils from coffee grounds using hydrodynamic cavitation in a Venturi tube. — 2025-Jul — https://pubmed.ncbi.nlm.nih.gov/40288159/ [8] — Krystyna Pyrzynska — Spent Coffee Grounds as a Source of Chlorogenic Acid. — 2025-Jan-30 — https://pubmed.ncbi.nlm.nih.gov/39942717/