RONA Wine Stem Basics Why Rona is the right choice for wine... One piece construction for maximum durability Barium crystalline composition is a safe alternative to traditional leaded crystal Laser cut rim for a clean, smooth delivery Bowl shapes that compliment and extenuate the wine tasting experience You simply cannot go wrong with a Rona stem. Now what size is appropriate? White wine is served in a smaller stem, typically 15 1/2 oz or less. Red wines are best served in larger glasses, 20 1/2 oz or more, Stems between 15 1/2 and 20 1/2 oz are perfect as a multipurpose glass, perfectly acceptable for either red or white.