How Long Does It Take for Your Coffee Pod to Decompose?
A new study reveals why you should carefully consider what coffee pods you use for your single-cup coffee machine.
A news release from the University of Tennessee-Knoxville tells readers that a Scientific Reports article has recently been published that assessed the life cycle of disposable coffee pods; and, shows why the coffee pod you choose for your single-cup coffee machine matters.
According to the report, single-cup coffee brewers occupy approximately 40% of US workplaces. The significance of this is that plastic coffee pods are placing a substantial burden on the economy and the environment by compounding the issue of recycling complex plastics. In fact, studies estimate that the throw-away pods landfilled in just 2014 alone, could encircle the earth more than 12 times.
Three Types of Coffee Pods
There are three type of coffee pods: Recyclable pods, compostable pods and reusable pods.
Recyclable pods far outnumber the other two types; however, just how recyclable a categorized recyclable pod really is…is another story. In fact, the majority of coffee pods today are actually made of non-recyclable plastic that can take hundreds to thousands of years to decompose. And those that are categorized as recyclable may not really be so recyclable in actual practice.
Recycling has a numbered system for categorizing the recyclability of packaging that you typically find stamped onto its surface. In the case of most coffee pods, that number is seven which technically is an “other plastics” category that widely cannot be recycled by most recycling plants. Those coffee pods of which the plastic can be recycled are categorized as number five plastic—namely polypropylene—which many plants can recycle and thereby result in more sustainable recyclability.
However, while some coffee pods are made of truly recyclable plastic, the problem lies in that the pods have to be cleaned by the consumer before being placed in with other recyclables. Otherwise, the pods are discarded with non-recyclable trash and add to the mountains of refuse already blotting American soil and our landscape. The report estimates that 9 billion pods ended up in landfills in 2014.
Reusable coffee pods are considered to be the ideal route for single-cup coffee machines. However, research has shown that most consumers prefer disposable pods due to the inconvenience of cleaning a reusable pod.
The solution to this problem then is to try to get manufacturers to focus on making disposable coffee pods that are designed as totally compostable products.
However, even this has its own problems. If the compostable pods are added to landfills, the end result is that anaerobic (no or low oxygen) conditions would occur while buried under all that other refuse, which would then result in greenhouse gases like methane being released into our atmosphere.
A more-sustainable disposal of compostable pods is under aerated conditions so that a lesser-greenhouse gas (carbon dioxide) is released, resulting in significantly less harm to the environment. Plus—and it’s a big PLUS—the compostable coffee pods can be used as excellent compost for growing crops and improving landscapes.
How Long Does it Take for a Compostable Pod to Decompose?
Performing a cradle-to-gate analysis that takes into account the multiple factors involved in how coffee pods of both recyclable and compostable natures compare, researchers assessed just how long it takes for a compostable pod to decompose into usable compost and the actual costs involved both economically and environmentally.
What the study found was that complete degradation of compostable coffee pods occurs within 46 days.
The study also revealed that on financial costs alone, it is cheaper to just dump any type of coffee pod into a landfill and be done with it—but not by much. Most importantly, however, was their determination that there are multiple other factors that demonstrate how using compostable pods and processing them as such, yields rewards that far outweigh the benefit of just landfill dumping the pods.
The researchers concluded that “…Ultimately, the compostable pods proved to be least impactful compared to the plastic pods while including a viable industrial-scale composting site at the end of its life (EOL).”
“Ultimately, I would like to see decisions made and in turn institutional change driven by such self-assessed life cycle assessments,” said Sustainability Researcher Komal Kooduvalli, who is an avid coffee drinker and the lead investigator of the study. “Especially in industries wherein composting for bio-based composites and/or products may be incorporated to create a truly circular pathway for such material flows.”
Timothy Boyer has a Ph.D. in Molecular and Cellular Biology from the University of Arizona. For 20+ years he has been employed as a freelance health and science writer. Timothy continues writing about science with a focus on the connection between coffee and healthy living. For continual updates about the benefits of coffee on your health, you can also follow Timothy on Twitter at TimBoyerWrites.
Image courtesy of Wikipedia Creative Commons, photographer attribution: Andrés Nieto Porras
“Scientific Reports Uncovers Komal Kooduvalli’s Compostable Coffee Pods Sustainability Research” University of Tennessee-Knoxville news release, July 8, 2020.
"Life Cycle Assessment of Compostable Coffee Pods: A US University Based Case Study" Kooduvalli, K., Vaidya, U.K. & Ozcan, S.; Scientific Reports 10, 9158 (June, 2020).