Tamarind fruit grows on a tamarind tree, which can be up to 15-25 meters tall. Both the trees and fruits of tamarind and sweet tamarind look the same. This exotic-looking fruit has a pod-like shape and is often curved. As the fruit ripens, the brown shell separates from the meat and becomes thin and brittle. When you crack open the shell, you'll see sticky brown pulp covering black seeds. The difference between these two kinds of tamarind is the flavor. Tamarind tastes extremely sour, while sweet tamarind is sweet, as the name suggests. Tamarind trees can be found all over Thailand and the harvest season is from November to February.