The results are in from a first-in-the-nation citywide reusable cup project, whose collaborators included restaurants such as Starbucks and suppliers like Berry Global.
Closed Loop Partners and the NextGen Consortium released a report Wednesday detailing results and lessons from the 12-week initiative, which began in August 2024 in Petaluma, California. It involved more than 30 restaurants making reusable cups the default for consumers’ beverage orders, with more than 60 return bins located throughout the city.
The partners want to build on this experience to launch longer reuse activations in select U.S. cities in 2026. But they acknowledge some areas of friction to examine in the meantime — including with the packaging itself.
The partners state in the report that the “lower comparative cost and greenhouse gas emissions of plastic cups offered the best pathway to financial and environmental viability for this reuse system.” However, some consumers expressed worries about microplastics, they said — especially when drinking hot beverages from polypropylene cups.
“Consumers also raised questions about the durability and safety of these plastic cups in industrial-grade dishwashers that use high heat for sanitation,” the report notes.
One issue with this is an awareness gap: Some consumers don’t realize that single-use paper cups often still contain some plastic, the report said.
CLP noted in emailed comments that there can be downsides to alternative materials. Stainless steel cups, for instance, require more material and energy upfront to produce, they said. Project partners selected the lightweight plastic cups for the trial based on avoided emissions in transport, alignment for washing at scale, cost efficiency and recyclability at end of life.
In the report, partners said that research and development around alternative cup materials must take into account business, environmental and consumer issues in order to “help unlock widespread adoption.” Collaboration will continue with brands and suppliers through the NextGen Consortium.
In a similar way that a consumer’s unboxing experience has become an important packaging consideration in e-commerce, the experience with a reusable cup compared with single-use could also sway consumer participation habits.
“Improving reusable cup design offers consumers an incentive to reuse above and beyond the environmental impact: an even better drinking experience than they have with single-use cups,” the partners stated in the report.
They got additional feedback on the cups via focus groups and interviews. Suggestions from consumers included making tighter-fitting lids to reduce spills. There were also form and function aspects consumers liked in reusable over single-use, namely the stronger nature of the cups.
The cups and branding for the Petaluma program were purple — a color not widely used in branding or other waste streams, the partners noted. But some consumers said making the interior of the cups white would better show the color of each beverage; this could also make inspecting for cleanliness easier after washing.
“We are open to using a different color, but continue to consider purple as a color that can be used in new environments, based on the successes of the Petaluma Reusable Cup Project,” Carolina Lobel, senior director at the Center for the Circular Economy at Closed Loop Partners, said in an email.
