When choosing an apple cider vinegar to replace a pharmaceutical for GERD, I tried the raw product that retained the mother. The ACV with the mother, unlike the more common run-of-the-mill product is raw, unpasteurized, and unfiltered. Less processing, in my opinion, offers a more wholesome product loaded good stuff.
Each morning, and again in the evening I mix 2 teaspoons of vinegar, with an equal amount of sugar (some use honey) plus cinnamon to make the mixture more palatable. Then I top the mug off with warm tap water. It actually tastes pretty good, if you like apple cider. After a week of drinking the ACV instead of taking the med prescribed for GERD, I am happy to say it seems to be working.