World Coffee Day: Coffee sneakers, mushrooms grown in coffee grounds

Each pair of Rens Originals is made with 150 grams of used coffee grounds (from roughly 21 cups of coffee) and recycled plastic.

Worldwide, people drink over 2.5 billion cups of coffee every day. Annually, a staggering 9 million tonnes of ground coffee is brewed around the world. On average, nearly 11 grams of fresh ground coffee goes into each cup. But only 1% of coffee actually goes into the cup - 99% is coffee waste, resulting in an estimated 18 million tonnes of wet, waste coffee grounds annually.

For most coffee waste, the landfill is its only destination. It is estimated that every year 6 million tonnes of coffee grounds are sent to landfills, the third-largest producer of methane gas behind fossil fuels and livestock. As the coffee grounds decompose, they release methane (greenhouse gas up to 24 times more potent than CO2) into the atmosphere, which has a significantly greater impact on global warming than CO2.

Before you order your favourite coffee, think of the burden of coffee plantation on the planet. Globally, out of the 50 countries with the highest deforestation rates, 37 are major coffee-growing regions. Out of the 25 biodiversity hotspots, 13 areas with delicate ecosystems are coffee-producing regions. Cultivating coffee accounts for 68% of the coffee industry’s climate impact. About 50% of the land used to produce coffee worldwide will be unproductive by 2050. In Latin America, the amount of non-productive areas could be as high as 88%. The World Wildlife Fund reports that 2.5 million acres have been cleared in Central America to grow coffee.

Coffee is the world’s second most tradeable commodity after oil and its burden on the planet is immeasurable. Rather than merely crying hoarse about climate change, some entrepreneurs are recycling coffee grounds in unusual ways. Two cases in point are Finnish brand Rens, which is making sneakers out of coffee waste, and Viennese Hut & Stiel, which is growing mushrooms in coffee grounds.

Coffee Sneakers

One day in 2018, two sneakerheads, Jesse Khanh Tran and Son Chu, sat in a café in Helsinki (Finland) discussing sneakers over hot coffee. Where the two Vietnam-born entrepreneurs met up turned out to be quite prophetic - a year later, Tran and Chu founded Rens Original, the Finnish sustainable startup behind sneakers made from coffee waste and recycled plastic (they claim they're the first).

“Every pair of Rens is made from approximately 150g of coffee waste, which is equivalent to 21 cups of coffee. Since we launched our Originals back in 2019, we have recycled over 250,000 plastic bottles and 750,000 cups of coffee. Coffee brings the features. Recycled plastic brings the flex and durability. Both create a sneaker built for your environment.” Tran told Moneycontrol.

Jesse Tran and Son Chu, cofounders of Finnish startup Rens which makes sneakers from coffee waste and plastic.

Every pair of Rens diverts 21 cups worth of coffee grounds from those landfills. Rens’ sneakers are waterproof and smell fresh. The coffee yarn dries 200% faster than traditional athletic apparel, keeping the shoes dry inside and out.

The coffee waste comes from cafés and businesses such as 7 Eleven, Starbucks, etc., collected locally near Rens’ supplier’s factory in Taiwan, Mainland China, and Vietnam. For the sneaker production, used coffee grounds are polymerised with recycled PET pellets and then spun into a yarn that is odour-proof, UV-blocking, quick to dry, and antibacterial. By using recycled plastic (rPET), Rens lowers the CO2 emissions generated by the upper's construction by 79% compared to virgin polymers used in most athletic footwear.

“There’s an interesting connection between Vietnam (where we were born) and Finland (where we have lived for the past 10 years)—Vietnam is the second-largest coffee producer in the world while Finland has the global largest coffee consumption per capita,” Tran added.

The World’s First Coffee Sneaker was launched via Kickstarter, raising over half a million dollars from over 5,000 customers in 100+ countries, and became the all-time largest fashion Kickstarter campaign in the Nordics. Rens coffee sneakers now sell in 100 countries across the world.

Mushrooms grown in coffee grounds

Every day, around 772,000 litres of coffee is consumed across Vienna, and 50 tonnes of ground coffee goes into the bin from espresso machines and coffee-makers. But not everyone stared and cursed the bane of coffee waste.

Florian Hofer and Manuel Bornbaum, two students of agriculture, emptied their pockets, rented a basement, bought the coffee waste and grew oyster mushrooms—using coffee grounds as soil.

Hut & Stiel, Hofer and Bornbaum’s company, picks brew waste from Viennese coffee houses, restaurants, hotels and retirement homes and processes it in an old building cellar.

Harvested mushrooms are delivered directly on a cargo bike. At the end of the process, the mushroom substrate used is composted and thus processed into fertiliser. This closes the coffee cycle and prevents waste.

Florian Hofer, cofounder, Hut & Stiel. (Photo: Preeti Verma Lal)

Rens is available globally via www.rensoriginal.eu (for the European countries), www.rensoriginal.com (for the US), and www.global.rensoriginal.com (for the rest of the countries). Rens’ second-generation sneakers are also available on www.indiegogo.com.