Along with providing a steady stream of material, a coffeehouse biorefinery would divert tons of food waste from landfills or the compost heap, Lin said at the ACS meeting. Starbucks Hong Kong produces about 5,000 tons of uneaten bakery items and coffee grounds. The $11.7 billion chain has exponentially more stores in western countries — 12,848 in the U.S., according to a tally on Wikipedia — so there's exponentially more waste in those places that could conceivably be turned into new raw materials. The next step is to test the refinery process at a pilot plant in Germany, according to Lin. No word on whether it will come to Starbucks' home turf.