Coffee contains both caffeine and acid-either or both may trigger reflux symptoms. I have heard of a low acid or acid free coffee. You might want to search for it on the web.
There is a brand of instant coffee called Kava, 90% acid reduced. I have GERD/hiatal hernia and allow myself 1 cup in the am.
Kava is an instant coffee. There is only one coffee that is approved by the FDA, Tested by Nestles, Kraft and PG&E, approved by the Department of Health, Health & Hospitals Corporation, the Veterans Administration and many many more, it is endorsed by the Vatican, it Certified Kosher and in addition to being low in acid, it retains all of its vitamins, minerals, antioxidants and micro-nutrients normally lost during roasting and it does all of this without adulterating the coffee or adding anything. Vist the site
www.healthwisecoffee.com No acid coffee would have no taste or flavor, the best you can get is naturally reduced acid which has almost 40% less pH acid than Maxwell House, Folgers, Hillsbrothers, etc.
I have acid reflux and coffee among other things irritate it. I used to buy Maxwell House low acid which didn't irritate it, however Maxwell House has done something to their coffee so it no longer has that good coffee smell to it.It has an obnoxious smell.
I love New England Vanilla Bean Coffee and I didn't want to give it up. It has irritated my stomach at times, so after it's done brewing, I add Vanilla creamer and water to it to weaken it enough so I can drink it. It smells and tastes great. I just have to drink about a third more of it.