How come when i eat things i get a sour bitter taste on my tongue that doesnt go away?

Try brushing your tongue with toothpaste and a brush while brushing your teeth, rinse with mouth wash and then rinse with water really well. Flosh your teeth and rinse your mouth. Keeping your mouth and teeth clean may solve this. It would help to know what you have been eating when you get this bitter taste. Often coffee will make your mouth feel bitter after consuming it.