economics Practical Magic

Those 'compostable' coffee pods that never actually break down in the dirt will disappear 300% faster if you turn them into biogas first.

March 25, 2026

Original Paper

Structural changes in PLA-based compostable packaging during mesophilic anaerobic digestion and their impact on composting biodegradation

Emmanuelle Gastaldi, Gaël Huet, Julie Lamarque, Florian MONLAU, Valentin Puchelle, Cecilia Sambusiti, Juliana Catalina Suarez Murcia, Paul Greuet, Sandra Domenek

SSRN · 6465231

The Takeaway

It reveals a 'chemical shortcut' for bio-plastics: the anaerobic digestion process used to create green energy pre-conditions the plastic, solving the common problem where 'compostable' items persist in the environment for years.

From the abstract

Residues from compostable packaging may persist in digestate after anaerobic digestion, raising concerns about their subsequent biodegradation. This study evaluated whether mesophilic anaerobic digestion (AD), followed by industrial composting, can improve the biodegradation of these residues. Compostable coffee capsules made of polylactic acid (PLA), poly(hydroxybutyrate-co-valerate) (PHBV), poly(butylene adipate-co-terephthalate) (PBAT), and poly(butylene succinate) (PBS) were used as model ma