Low acid coffee is a type of coffee that, when brewed at normal strength, registers 5.0 or more on the pH scale — the comparative hydrogen ion concentrate scale that identifies bases and acids. The acid in coffee can be reduced in the roasting process or in the brewing process, and studies show these methods can result in acid reduction by between 25% and 67% without affecting the coffee’s taste or aroma. Several companies currently offer low acid coffee beans in a variety of flavors. Low acid coffee is considered particularly beneficial for sufferers of acid reflux or gastrointestinal problems.
Regular coffee tends to be fairly acidic, so it increases the production of gastric acid levels and decreases pressure in the esophageal sphincter. This can irritate the stomach and cause or exacerbate indigestion, heartburn, and acid reflux symptoms. Low acid coffee prevents an increase in gastric acid and a decrease in esophageal pressure, stopping this process at the source. Stomach irritation is greatly reduced, resulting in reduced gastrointestinal discomfort.
The first method for producing low acid coffee involves special roasting techniques designed to reduce acid by as much as 25% without having a negative effect on the taste. The two most prominent US producers of low acid coffee are Hevla and Puroast. Hevla uses a completely natural high pressure steam and vacuum process, performed when the coffee beans are still green. It reduces irritants formed during coffee roasting, reducing the acid-content. Puroast also uses an all natural proprietary process that does not use additives, does not manipulate the coffee beans through an extraction process, and does not create the acids that affect the stomach.
Puroast has sponsored scientific research on the use of their low acid coffee. Recent studies conducted by the University of California at Davis showed that the Puroast brand contains at least 50% less acid than other brands. Consumer research concluded to 90% of people who consumed this coffee experienced relief from the symptom gastrointestinal of discomfort.
The other method for creating low acid coffee involves a simple but time-consuming cold brewing process. Regular ground coffee can be used, and some manufacturers claim cold brewing results in up to 67% less acid. Grounds are added to cold water and allowed to steep for 12 hours, often overnight. When decanted, the resulting concentrate can be prepared as desired by adding hot water or blending with ice. Special cold-brewing machines are also available.