Woodland’s Puroast Coffee Co. thinks coffee drinkers prefer their brew with less acid. And Keiretsu Forum, an angel investment group, is banking on it. The coffee company got a $700,000 jolt of second-stage seed funding from the Bay Area investors. The money will be used to expand marketing and production of the free trade and organic coffee. The beans are roasted using South American methods that produce a brew with half the acid of regular coffee. This claim was validated by University of California Davis research. Puroast could have a ready market. In 2006, Americans spent $14 billion on digestive acid medications.