Riddling, or remuage, is the process of gradually turning and tilting bottles of sparkling wine (produced by the traditional method) to collect the sediment from the secondary fermentation into the neck of the bottle, so it can be frozen and expelled during disgorgement; this operation is performed on special wooden racks called pupitres, and a skilled riddler must turn each bottle a precise fraction of a turn over a period of weeks, gradually increasing the angle; in poetry, riddling represents a slow, patient, and disciplined uncovering, the gradual revelation of clarity from cloudy fermentation, and it serves as a potent metaphor for the poet's persistent refinement of a work, the turning and adjusting that gradually brings the poem into focus, much as the riddler's art reveals the brilliant, clear wine beneath the sediment.