This is a wine with high levels of acidity. It comes from under-developed wines that are lean.
A wine with noticeable sugar. It is only good when it is balanced with the acids so it would not have an overly sweet taste.
These are wines that does not have a rich fruity flavor. It has a very dry taste and high in acidity due to aging in vats.
Sour wines are described as an unbalanced wine with an extreme and powerful acetic acid causing it to taste like a vinegar.