A smoking article includes an aerosol-generating substrate comprising a flavor delivery material for thermally releasing a flavorant. The flavor delivery material comprises a polymer matrix and a plurality of domains of a flavor composition dispersed within the polymer matrix. The flavor composition comprises a flavorant mixed with one or more triglycerides including at least 30% by weight of triglyceride having at least one carboxylic acid having a chain length of greater than 12. The flavorant is releasable from the polymer matrix upon heating the flavor delivery material to elevated temperatures.