Summarize:

The stem of the wineglass is designed so your hand doesn't touch the bowl and spread fingerprints over the glass or warm the wine with your body heat. They also make the glass easier and more comfortable to hold, allowing you to slowly sip and savor your wine.Because wine is meant to be sipped, you want glasses that are comfortable to hold for a long amount of time. Stemless wine glasses are more durable because they don't have a delicate stem that can crack, chip, or break. But when you hold a stemless glass, the heat from your hand causes the wine in the glass to warm up, which alters its flavor profile and drinkability. To make your wine experience more enjoyable, go with glasses that have a stem.Stemless glasses will really cause white wines, sparkling wine, and champagne to warm up and make it less enjoyable.
Pick glasses with long stems to sip the wine comfortably. Avoid stemless wine glasses so your wine doesn't heat up.