T.R. grinned and pantomimed sticking a finger down into something and then lifting it to his mouth. "Literally taste. If the oil was sweet, it was low-sulfur. Sour crude, on the other hand, needs extra refining to take the sulfur out, so it sells at a discount. There’s a lot of sour in the Gulf, especially down Mexico way. Anyway, I been buyin’ it up."