Skip to main content

Scientists have discovered a new purpose for your leftover coffee grounds

Don't throw out your coffee grounds just yet

Coffee grounds
Caio / Pexels

Many coffee drinkers find unique ways to repurpose leftover coffee grounds, such as to enhance the nutrients in the soil of houseplants. But recently, Australian scientists have discovered another interesting purpose for your leftover coffee grounds. Researchers found that concrete can be made up to 30% stronger by adding charred coffee grounds to the mix. This interesting discovery could be the first of many ways to solve environmental challenges related to coffee waste and sand extraction.

Researchers from the Royal Melbourne Institute of Technology (RMIT) explain: “The disposal of organic waste poses an environmental challenge as it emits large amounts of greenhouse gases, including methane and carbon dioxide, which contribute to climate change.” RMIT University engineer Rajeev Roychand warns that “the world produces a staggering 10 billion kilograms (22 billion pounds) of coffee waste globally each year.” The problem is that most coffee waste ends up in landfills instead of being repurposed for other useful purposes, such as the one in this unique discovery.

Recommended Videos

RMIT engineer Jie Li also weighs in, noting that “there are critical and long-lasting challenges in maintaining a sustainable supply of sand due to the finite nature of resources and the environmental impacts of sand mining. With a circular-economy approach, we could keep organic waste out of landfills and also better preserve our natural resources like sand.” Researchers do caution that this discovery is in its early stages, and additional research is still needed to assess the “long-term durability of their cement product” with added coffee grounds.

Emily Caldwell
Emily is a freelance journalist with a focus on food, beverage, health, fitness, and travel content. She loves to travel to…
Peanut butter coffee: A creamy twist on your favorite brew (and how to make it)
3 variations of peanut butter coffee
Peanut butter

Unlike french vanilla or hazelnut coffee, the term "peanut butter coffee" isn't one you've likely heard often (or at all). I first encountered peanut butter coffee on an Instagram reel where a fellow coffee lover showed a latte brewed into a cup filled with peanut butter. Since I love creamy peanut butter almost as much as I love coffee, it's safe to say the idea of peanut butter coffee intrigued me.

As it turns out, Alex Zapata's variation of peanut butter coffee is only one of the many ways creative coffee lovers use peanut butter and coffee together. If you're as intrigued about this flavor pairing as I am, here are three ways to try peanut butter coffee for yourself.
Plant-based peanut butter coffee

Read more
How to make whipped coffee in just 5 minutes
Make coffee with a thick, fluffy foam on top
how to make whipped coffee pexels martin munkacsi 30043555 8548113

As an avid coffee drinker, I think whipped coffee is incredible; it even has a unique look.

Whipped coffee almost resembles coffee that has been topped with whipped peanut butter, yet no peanut butter is used in this unique beverage. Instead, this distinctive coffee drink is made with instant coffee, sugar, hot water, and cold milk (or, if you're like me on a low-sugar, low-carb diet, you can swap granulated sugar for a zero-calorie sweetener like monk fruit). You may have heard this drink referred to as a Dalgona coffee, which comes from a Korean sugar candy with a "whipped" appearance.

Read more
How to clean a coffee grinder for a fresher, better-tasting brew
What to know about keeping your coffee tools clean
Coffee bean grinder machine

Though we all want to brew delicious coffee at home, most aren't thrilled about cleaning our coffee gear. Even remembering to run regular cleaning cycles on my coffee maker seems inconvenient. While it's not the most thrilling of tasks, keeping your coffee tools clean is non-negotiable for enjoying a fresh-tasting cup of coffee.

Your coffee grinder plays a critical role in your coffee bar, but when did you last clean it? If you can't answer, this guide is for you. I've put together a guide of what you need to know about how to clean a coffee grinder, an essential coffee tool most of us forget to clean.
Why cleaning your coffee grinder matters

Read more