Acid reflux DOES cause burping.
What Is a Burp?
Burping is the body's way of expelling excess stomach gas. The stomach will fill with gas by taking in too much air (air contains the gases oxygen and nitrogen) while eating and drinking. The stomach will then expel that air by pushing it back up through the esophagus. You will find that you may burp more when drinking carbonated beverages due to their carbon dioxide content. Drinking through a straw may also cause you to intake excess air.
Why Acid Reflux Causes Burping
Acid reflux, also known as gastroesophageal reflux disease or GERD, is a condition in which the normal acids in the stomach designed to digest food escape and are pushed in the wrong direction toward the esophagus. The body's natural reaction to these foreign acids in your throat is to swallow repeatedly to push them back down, which introduces excess air into the stomach, and subsequently requires the stomach to expel the air through a burp.