Sure, your beer comes to you in its own packaging, a package that you could hypothetically drink the beer out of, but doing that does a disservice to the beer and to your potential enjoyment. Pouring the beer from the bottle, can or whatever other vessel it originally came in opens you up to a world of possibilities.
A glass will enhance virtually every aspect of a beer. You get to gaze upon its beautiful appearance, take in all of the aroma it can offer which in turn heightens the flavor compounds making for a more vibrant and fulfilling experience. Having the beer in the glass allows you to marry aromas and flavors together as you are actually able to taste while smelling the elixir, simultaneously! Drinking from a bottle or can only allows you to partake in one at a time.
The act of actually pouring the beer is very important as well as it helps the carbonation to create a head on the liquid. The carbonation in the glass further aids and enhances aromas, flavors and mouthfeel. The shape and style of glass will further affect the way carbonation behaves with the motion of the beer traversing the topography of the glass.
There are many types of glasses and they all can offer specific enhancements to certain beers. There is no one correct glass for a beer, use what glass is right for you, and gives you the experience you are looking for. Below are just a few options…
Tulip: A tulip is a glass that is stemmed and has a shape reminiscent of a tulip flower. The top of the glass bows outward to capture the head and push aroma out, whereas the body is rounded. As you progress through a beer it must constantly roll over the contours of the glass keeping the aroma and body lively. A tulip can be ideal for a variety of style including saisons, lambics, IPAs, Belgian strong ales and many more.
Snifter: A snifter is traditionally a glass used for spirits, may it be whisky, brandy or cognac. With its usually short stem, wide bowl with an increasingly tapered top this is an ideal glass to capture and concentrate aromas and flavors. This style comes in a variety of sizes including mini as well as oversized versions. A snifter is always a great choice for barleywines, imperial stouts and other brews on the stronger end.
Goblet: A goblet is yet another stemmed glass with a very widemouthed and deep bowl perched atop it. The deep bowl shows the elegance of the beer within while typically giving ample head space. The wide mouth enables deep and full sips. This is an ideal glass to indulge Trappist/Belgian ales, Berlinerweiss and even a gose.
Weizen Glass: A weizen glass is the ideal vessel for your German wheat beer needs. This glass is tall with a tapered body with the larger end being at the top. This enables you to see all the hazy glory you are about to consume, and these larger glasses (typically about .5 liters) give you ample room for the lively head the wheat beer is sure to adorn. A glass perfect for all your wheat needs.