You really want to look at varietals of coffee themselves as opposed to vendor in terms of acidity. Both Kona and Jamican Blue Mountain are relatively low in acid compared to other varietals. You want 100 percent in those cases, not blends with them, and unfortunately they aren't cheap either. They are also some of the best varietals you can buy, in my opinion. Light roasting your coffee as opposed to espresso or french roasting them is also going to result in less acid. This site lists acidity levels for other varietals, your mileage may vary. http://www.coffeebeanqueen.com/coffee-bean...y-and-body.aspx In addition to pursuing lower acid varietals themselves there are some companies that use proprietary roasting processses to lower the acid, such as these guys: http://www.puroast.com http://www.hevlacoffeeco.com