Sweet crude oil

Sweet crude oil is a type of petroleum. The New York Mercantile Exchange designates petroleum with less than 0.5% sulfur as sweet.

Petroleum containing higher levels of sulfur is called sour crude oil.

Sweet crude oil contains small amounts of hydrogen sulfide and carbon dioxide. High-quality, low-sulfur crude oil is commonly used for processing into gasoline and is in high demand, particularly in industrialized nations. Light sweet crude oil is the most sought-after version of crude oil as it contains a disproportionately large fraction that is directly processed (fractionation) into gasoline (naphtha), kerosene, and high-quality diesel (gas oil).

The term sweet originates from the fact that a low level of sulfur provides the oil with a relatively sweet taste and pleasant smell, compared to sulfurous oil. Nineteenth-century prospectors would taste and smell small quantities of oil to determine its quality.