Like new, Riedel cognac glasses. Set of 2 The Cognac Hennessy glass is perfect for providing the ideal tasting experience of Cognac: fruit, body, finesse and fire. Cognac is mainly served in wide balloon-shaped glasses - in spite of the disadvantages which this shape has for the enjoyment of cognac. The finely tuned shape of this glass harmonizes aroma and taste, tempers alcohol and stringency of the palate, and emphasizes the bouquet. The thin tulip-shaped glass allows its contents a very small evaporation surface.