Can Recycled Coffee Pulp Help Save Rainforests?

Whether it’s composting our coffee grounds, spreading them around in our gardens to ward off pests, or creating a paste to kick our facial routines up a notch, many of us have found fun and novel ways to get the most out of our coffee waste.

And it’s not just individual consumers who are looking to recycle their coffee waste. Many corporations have made solid efforts to find versatile ways to use typically disposed of elements of the coffee bean. And for a pair of scientists in Costa Rica, the process of recycling coffee beans could offer a novel way to save and regenerate entire rainforests.  

In Costa Rica, coffee was first grown in the 1700s, with the Arabica coffee plant spreading roots in the country’s central valley. Arabica is notoriously finicky, but the valley’s geography allowed for the right temperature and altitude to grow everyone’s favorite bean. The industry quickly snowballed, and by the 19th century, the government was offering plots of land to potential coffee farmers at no cost. As such, Costa Rica is the 13th largest producer of coffee today — but the production of some 1.5 million bags of coffee annually doesn’t come without consequences. 

Costa Rica’s coffee farming industry faces two major challenges: rainforest destruction and waste disposal. Unfortunately, the coffee industry produces a huge amount of waste: every year, more than 23 million tons of waste, in fact. And much of that is from something called “coffee pulp.”

The unprocessed form of coffee is a bright red or yellow fruit called a coffee cherry. To get to the coffee bean, which is actually the cherry seed, most manufacturers will strip off the outer fruit before drying and roasting the beans. Left over from this process is the coffee pulp. It is a heavy mass of fruit and skins and other organic matter.

By weight, half of every harvest ends up as coffee pulp, which manufacturers then have to pay to have carted off to a landfill or compost site. It’s expensive and not good for the environment — and both prices are passed on to the consumer, in the end.

The second problem is deforestation. Due to stiff competition, farmers are always pushed to develop new land. Unfortunately, while converted rainforests start out being very productive farmland, they don’t stay that way for very long.

Once exhausted, these fields are then left to be reclaimed by the rainforests. It is a painfully slow process hindered by invasive plant species originally brought in to help feed livestock. The biggest offender is a plant called palisade grass, an African species that can grow up to 16 feet in height if left unchecked. While fast-growing grasses are great for grazing cattle, they can be almost impossible to get rid of once the herd has moved on to greener pastures.

Incredibly, these two major problems may actually be used to solve each other. The traditional solution to deforestation has been the replanting of trees, but that is extremely labor and cost intensive, so two ecologists from the University of Hawai’i at Manoa came up with a groundbreaking new solution: coffee pulp.

In an experiment published in the journal Ecological Solutions and Evidence, the ecologists spread untreated coffee pulp over a test patch of palisade grass and then observed it for several years. The results were astonishing. After two years, 80% of the plot was covered by trees. Some of the trees had grown up to 15 feet in height, including some giant tropical species that could someday reach as high as 60 feet. For comparison, in the nearby control plot, trees only grew over 20% of the ground.

So, how does it work? How can old coffee leftovers push a rainforest into overdrive? The secret is laying on the coffee pulp nice and thick. By spreading out a layer of pulp 20 inches deep, the researchers were effectively able to smother the palisade grass.

The pulp covering slowly cooks the grass, asphyxiating it until it has died and begins to decompose. The pulp is so effective that it even kills the roots and rhizomes deep underground, ensuring that they will never grow back. The process is similar to leaving a tarp out in your backyard until the grass goes brown, but on a much larger scale. The pulp and dead grass then decompose, creating a nutrient-rich layer of fertile soil.

The decomposition then attracts insects, which in turn attracts birds. The birds drop seeds into the soil. And with the help of seeds blown in by the wind, this all results in an explosion of new and diverse growth. The multiyear process is by far the most effective and economical solution around.

This is a major win for both Costa Rican coffee farmers and ecologists, but there are a few stumbling blocks that could still hamper widespread application in the future. First, the decomposing coffee pulp can be pretty unpleasant: the smell is often described as putrid, which makes it doubtful that many towns would tolerate a large-scale operation nearby. Second, it is not clear what impact this might have on the local water supply, so further studies will have to investigate the risks of contamination.

The third hurdle is politics. Several years ago, a major orange juice company teamed up with a local protected area to spread discarded orange peels over a pasture. Unfortunately, the company’s biggest competitor complained to the government, claiming the operation was just an excuse for illegal dumping. The program was ultimately shut down.

Thankfully, most of the coffee growers are small local operations who are all likely to gain from recycling coffee pulp. With cooperation between coffee farmers, ecologists, and local government, this process really could be one of those rare all-around beneficial situations that coffee enthusiasts all over the world will be able to taste in their cups, their wallets, and even their lungs. 

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