Wine clarity refers to the amount of undissolved matter floating in a wine.
A wine with greater clarity appears purer. Light passing through a wine with great clarity appears sharp and brilliant. This rule of thumb goes for all wines, including red wines with great depth of color.
A wine with less clarity may appear cloudy or hazy when viewed in a wine glass.
Clarity is commonly used as a measure of quality, as it directly relates to how much or how little a wine was fined (refined) during its production. A wine with greater clarity is thought to be purer and of higher quality.