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.[4]
^"Oil markets explained". BBC News. 'Sweet' crude is defined as having a sulphur content of less than 0.5%.
^Szymon Wlazlowski , Björn Hagströmer & Monica Giulietti (2011). "Causality in crude oil prices". Applied Economics. 43 (24). Applied Economics (Vol. 43 Issue24): 3337–3347. doi:10.1080/00036841003636250. S2CID154524771. Crudes are considered to be sweet when the sulphur content does not exceed 0.5% and sour otherwise.