Every feature wine glass is oriented around swirling, sniffing and maintaining wine’s temperature, all to enhance wine’s scent. There are all sorts of wine glasses, some made for specific styles of wine, but one amazing single all-purpose wine glass is really all you need. Stemmed glasses with large bowls are flattering to wines by focusing our attention on their aromatics.
My favorite features a large bowl that holds 6 ounces of wine with enough room to swirl so we can amplify wine's sent. Wine is loaded with volatile components that evaporate easily, aromatic compounds like esters and aldehydes. The bowl should narrow at the top to focus these smells. You don't want to fill it pass the widest point, so that there's enough room to swirl and sniff.
The stem was designed for holding the glass. This allows for the wine to keeps the proper temperature by preventing your fingers from touching the bowl. Glass quickly transmits body heat and even gentle warming will change the wine's flavor. Hold the stem as if you are holding a pen or a pencil.
Use the base of the glass to make zero's for the perfect swirl.