Caffeine, as found in both coffee and tea, is known to cause acid reflux in some people. Tea contains less caffeine than coffee, and decaffeinated coffee contains only 2mg to 5mg of caffeine per cup. The type of coffee roast may also affect heartburn. Lighter roasts, or breakfast coffees, are often guilty of containing more caffeine. However, in some people, GERD symptoms will be related to the darker roast, due to these beans being more acidic. In this case, it is the acidity of the caffeine which triggers the onset of acid reflux.
In general, though, caffeine is often omitted from GERD-friendly diets for another reason. Coffee relaxes the lower esophageal sphincter (LES). This means that this valve does not close tightly above the stomach, allowing acid back up. It is thought to explain why people who eliminate coffee in all its forms report a definite easing of GERD symptoms. Try non-mint herbal teas, non-citrus juices, and water instead.