Riedel has introduced a jet-black glass called the Blind Blind Tasting Glass. In addition to concealing wines' grape, type, region, producer and vintage, as is the case in normal blind tastings, this glass hides wines' color, (white, red or rosé), depth of color, clarity, brilliance, and effervescence.
The Blind Blind Tasting Glass was designed for wine drinkers who don't want to form pre-conceived judgments prior to tasting, who want to taste fully blind. Given that humans' first sense in judging wine is sight (in fact, blind-folded tasters have not infrequently confused red and white wines), this glass removes all visual cues. Beyond color, the Blind Blind glass precludes immediately judging, for example, a pale-red Barolo as thin, or a deep purple pinot noir as rich. It is indeed the world's first double-blind glass.
The Blind Blind Tasting Glass (8400/15) employs Riedel's most versatile bowl, the Zinfandel/Chianti (8-7/8" high with a 133/8 ounce bowl) and like other glasses in the Sommeliers collection is hand-made of full-lead crystal. The glass achieves its blackness through the addition of manganese oxide; a little of this metal turns glass purple, a little more turns it pitch black.