Why would a person taste bad?

Taste is one of our senses, the receptors for which are located in the mouth, primarily on the tongue. There are sour, sweet, bitter, salty and umami tastes. Unpleasant taste sensations are evolutionarily laid down to warn against the use of spoiled foods, potentially dangerous substances. However, the taste is not always able to help us out and the taste of poisonous mushrooms may not differ in any way from the taste of edible ones.