Wet burp

A wet burp is a slang term for a burp where small amounts of liquid are regurgitated. It is different from vomiting—one who experiences a wet burp often has an acidic/burning sensation in the mouth, which can be unpleasant.[1] In addition to the cause of this typically being related to acid reflux disease, it also occurs if an individual consumes too much food for the stomach to handle. This results in the partially digested contents of the stomach to back up into the esophageal canal, which may cause small amounts of the bile and food to come up during the burp. This may also be accompanied by excessive, deep burping. Wet burping can also take place if someone consumes food too quickly, resulting in air being trapped throughout the stomach's chyme. When the air is released, it carries small amounts of chyme with it.

According to Charles Bourland, a consultant for the NASA Food Technology Commercial Space Center, if one burps in outer space, it is usually wet because the liquid and gas do not separate in the stomach like they do on Earth.[2]