Dr. Oz and Greenopedia.com both have lists of foods organized by degree of acid-production. Rense.com and EnergiseForLife.com feature comprehensive lists of both acidic and alkalinic foods, while Healthy.com lists the top seven foods that cause acid reflux specifically.
On his website, physician Dr. Oz features a list of 25 common acid-promoting foods. These are listed from neutral to the most acid-producing. According to the list, Parmesan cheese and American/cheddar cheeses are the most acid-producing foods.
Greenopedia.com features a more comprehensive list of acidic foods by degree. The chart categorizes foods according to one of four designations -- very low acidic, low acidic, moderately acidic and highly acidic. Within the chart, though, the foods are listed alphabetically, not by degree of acidity.
Rense.com has a chart that lists both alkaline and acidic foods. The chart categorizes the foods according to type, such as vegetables, fruits, grains, beans and dairy. The chart doesn't offer levels of acidity or alkalinity, though.
EnergiseForLife.com features a detailed chart of both acidic and alkaline foods. The chart includes a scale ranging from highly alkaline foods to highly acidic foods categorized by food type. The chart is available as a .pdf file under the Resources tab.
Health.com offers a resource for foods that specifically cause acid reflux. This resource lists the top seven foods that cause acid reflux and why they do so.