Starbucks Japan Feeds Cows With Coffee Grounds

Every year, millions of tonnes of used coffee grounds go to waste — composted, incinerated, or buried in landfills. But in Japan, a surprising new use has emerged: feeding cows. Instead of discarding the leftover grounds from thousands of espresso shots, Starbucks Japan and contact lens maker Menicon have found a way to turn this byproduct into nutritious animal feed — with measurable effects on milk quality.

Yes, cows fed a diet including fermented coffee grounds now produce milk with lower somatic cell counts — a key indicator of milk quality — making it better suited for dairy products like cheese and yogurt. The method has already made its way into some Starbucks Japan drinks.

How Coffee Grounds Became Cow Feed

Coffee is the most traded agricultural commodity in the world. Between 2009 and 2010 alone, 9.34 million 60kg bags of coffee beans were shipped globally. Yet after roasting and brewing, the leftover grounds are rarely put to high-value use. Most become compost, fuel, or landfill.

To address this waste, Starbucks Japan partnered with Menicon, a company better known for contact lenses. Menicon had been researching fermentation techniques to make better use of rice straw — but ended up developing a lactate fermentation process that could also upgrade coffee grounds.

The technique enhances the nutritional profile of the grounds, turning them into a viable component of cattle feed. This isn’t just diverting trash; it’s creating a functional ingredient with measurable benefits.

Improved Milk Quality Backed By Data

According to reports, Kawai, a professor at Azabu University’s School of Veterinary Medicine, evaluated the results. He pointed to somatic cell count — the number of white blood cells in milk — as a primary marker of milk quality. Lower counts indicate healthier milk, better taste, and suitability for secondary dairy products such as yogurt and cheese.

Cows fed the fermented coffee-ground-enriched diet produced milk with significantly lower somatic cell counts than those on a standard diet. That means better milk, with potential advantages for cheese yield, texture, and flavor stability.

Logistics: Collecting Coffee Waste At Scale

Starbucks Japan operates nearly 1,000 stores nationwide, all of which generate used coffee grounds daily. To turn this into a reliable feedstock, logistics had to adapt without adding emissions or costs.

The solution? Starbucks modified its refrigerated delivery trucks — the ones that carry cold items — to include a dedicated compartment for transporting coffee grounds. This eliminated the need for extra vehicles, maintained hygiene, and ensured carbon-neutral collection.

The collected grounds are then sent to a central facility where the lactate fermentation process is applied, boosting their nutritional value before being mixed into feed rations.

From Farm To Cup: The Feedback Loop

The end result? Milk from cows that ate the enhanced feed is now being used in some Starbucks Japan beverages. Customer feedback has reportedly been very positive.

Beyond the cup, the fermented grounds aren’t wasted afterward. They’re repurposed again — this time as organic fertilizer for growing produce, completing a circular system that touches both food and beverage.

Frequently Asked Questions

What is lactate fermentation and how does it work on coffee grounds?

Lactate fermentation is a microbial process that breaks down organic material in an anaerobic (oxygen-free) environment, producing lactic acid and improving the nutritional profile of the substrate. In this case, it’s used to enhance the feed value of used coffee grounds, making them more digestible and nutritious for cattle.

How much coffee waste does Starbucks Japan produce?

While the article doesn’t state an exact figure, Starbucks Japan operates close to 1,000 stores, each generating used coffee grounds daily. The exact tonnage isn’t given, but the scale is significant enough to require a dedicated logistics solution using refrigerated delivery trucks.

What is a somatic cell count and why does it matter?

Somatic cell count measures the number of white blood cells in milk and is a key indicator of milk quality. Lower counts mean healthier milk, less risk of infection, and better suitability for products like cheese and yogurt. Milk from cows fed fermented coffee grounds showed significantly lower counts.

How did Starbucks solve the problem of collecting coffee grounds from so many stores?

Starbucks modified its existing fleet of refrigerated delivery trucks by adding a special compartment for transporting coffee grounds. This avoided the need for additional vehicles, reduced costs, and kept the process hygienic and carbon-efficient.

Is the milk from these cows being used in all Starbucks Japan drinks?

The article states that the milk is “” (quite popular as an added milk) in Starbucks Japan but does not specify if it’s used in all beverages. It is confirmed to be in use in select drinks based on positive customer feedback.

What happens to the coffee grounds after the cows are done with them?

After being consumed by the cows, the fermented coffee grounds are further repurposed as organic fertilizer for growing crops. This completes a circular lifecycle from coffee shop to cattle feed to farm produce.

FrontStreet Beans for Lactation & Fermentation Experiments

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