Asphalt is the densest liquid refined product produced by a refinery, but only stays liquid if stored and transported heated. It becomes a solid if allowed to cool to normal atmospheric temperatures.

Asphalt is primarily made up of large, dense molecules called asphaltenes.

The major uses for asphalt are as a binder for road paving and in construction materials such as asphalt roofing shingles.

Although asphalt is generally valued lower than crude oil, it is considered a value-adding product because it is made from the densest, lowest-value part of crude oil, the vacuum resid, yet is typically valued higher than residual fuel oil. So the value to a refinery from making asphalt comes, not from the high value of the product, but from the low cost of the feed stock.

A typical refinery does not produce any asphalt, because of the relatively small end market. So it is generally considered to be one of the specialty products.