Quality differential represents the price difference between various grades or qualities of the same commodity, reflecting differences in processing costs, end-use value, or market demand. These differentials can be positive (premiums) or negative (discounts) relative to benchmark grades. Quality differentials change based on relative supply-demand conditions for different grades.

Quality differentials provide economic signals that guide production, processing, and trading decisions throughout commodity supply chains. Wide differentials may incentivize quality upgrades or grade switching, while narrow differentials suggest balanced markets. Understanding differential patterns helps assess market conditions and identify arbitrage opportunities between quality grades.

Real-world example: Light sweet crude oil trades at a $8 per barrel quality differential above heavy sour crude due to easier refining and higher valuable product yields, though this differential narrows when heavy crude refineries operate at high utilization.