An apparatus and method are disclosed and pertain to a lid for use with a container having a rim and an opening where volatile esters from an aromatic compound are dispersing into the environment and for enhancing the identification of the volatile esters. The lid is comprised of a generally planar laterally stabilized gas restrictive material for decreasing the dispersion rate of the volatile esters, resulting in increased concentration of the volatile esters within the container and enhancing the identification of the volatile esters emitted from the aromatic compound. The lid includes a surface for coupling to the rim in a manner that laterally stabilizes the lid so that it remains sufficiently fixed to the rim during agitation of the container. The surface also permits the lid to be removed from the rim.