system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why do some foods have an after taste - And what causes the after taste?
gpt
There are two things you need to know; how taste buds work, and how saliva works

Saliva is the first part of digestion, believe it or not. The food is actually being broken down at a molecular level before you even swallow it!

Taste buds are sort of similar to the nerves you have on your skin. Your hands are really good at understanding the texture of what it touches, whereas your shoulder for example, is pretty bad at it. You can think of taste buds in the same way. Taste buds are just very very specialized nerves (sort of), that can understand what different things taste like.

The regular flavor of something is just how the taste buds process that food. The *aftertaste* comes when your taste buds start tasting the food *after* it's been broken down. The few particles of food left in your mouth after you swallow are still being broken down, and your taste buds do their job by "tasting" these leftover compounds.