I get excessive sticky white mucus build up in the larynx area, is this likely to be pepsin, bile or acid, it never burns my throat?

Throat mucus. Throat mucus can come from chronic allergies either in the air or also from foods you're eating. Frequent causes are dairy products. Mucus is not the same as pepsin, bile, or acid -- but if you have gerd your throat can be irritated. Chronic cough can come with this. Please discuss this with your physician.