The tulip is the glass to reach for when the beer’s aroma is the main event. Its profile is a double curve: the bowl narrows as it rises, then the lip flares back outward. The narrowing concentrates volatile aroma compounds into a small headspace above the beer; the flare then delivers that concentrated air straight to your nose as you tilt the glass. Almost every serious tasting glass, from the Rastal Teku to the branded Belgian tulips, is a variation on that one idea.The flared rim earns its keep a second way. It supports a head rather than letting it slide off, which matters for Belgian ales that are bottle-conditioned and lively. Many branded tulips, Duvel’s included, are also nucleated: a small etched patch on the inside of the bowl gives dissolved carbon dioxide a surface to form bubbles on, so a steady column keeps rising and the head continually renews itself instead of collapsing after two minutes.Most tulips are stemmed or footed, and that is deliberate too. A hop-forward IPA or a 9% tripel is at its best over twenty or thirty minutes, and a stem keeps your palm off the bowl so the beer warms at its own pace rather than yours. Hold it by the stem, not the bowl.Suits: IPA and double IPA, Belgian tripel and strong golden ale, saison, wild and sour ales, and just about anything you want to think about rather than simply drink.