If you want to test to see if your stomach acid is low, you can try this simple test at home: On an empty stomach, such as first thing in the morning, drink an 8-ounce glass of water into which you have mixed one-quarter teaspoon of baking soda (sodium bicarbonate). Using a clock or watch, measure how long it is before you burp. If you have enough stomach acid, you should burp within two minutes. If you haven't burped within 5 minutes, you can stop timing.