Many people complain of heartburn almost every day. Heartburn occurs when stomach acid backs up into the oesophagus (the tube that carries food from mouth to stomach) causing a painful burning feeling in the chest or throat. It also leaves the mouth with a foul acidic taste.
Occasional heartburn is normal and should not cause alarm. However, recurring acid reflux, as heartburn is referred to, may be an indication of gastroesophageal reflux disease (GERD) and should be attended to.
https://www.standardmedia.co.ke/evewoman/article/2001299116/six-commons-foods-that-are-causing-you-heartburn
Six commons foods that cause heartburn