In college, my buddies and I took pride in getting the most beer possible into our glasses. We'd heckle any bartender who filled the top inch or two with foam.

At parties, we filled our red plastic cups to the brim with Bud or Miller Lite or Icehouse from the keg tap. If the beer came in a bottle or can, we drank it that way.

No need for foam, we always said.

Man, were we dumb.

Beer experts, fans and brewers know better. Foam, or head as it's called, is important, even necessary.

Why? "Aroma! Aroma! Aroma!" says Dan Kopman, co-founder of the Schlafly brewery in St. Louis.

But I hear all sorts of excuses for the no-foam argument: I want to fit all 12 ounces in the glass. I don't want it to overflow. I don't want bubbles near my nose on the first few sips.

Bah humbug!

Much of beer's flavor is contained in the aroma, which is released by the agitation of a good strong pour. Our tongues are far more limited than our noses in sensory perception.

"Tasting is a lot about the aroma. You'll pick up the aroma first and that'll create the true impression and really tell you so much more about the beer you're about to drink," says Florian Kuplent, a brewmaster at Anheuser-Busch and the Michelob Brewing Co.

Don't believe it? Go to the store and pick up a six-pack of a good, aromatic beer — maybe an American pale ale or a big Belgian ale. Take a sip of one from the bottle. Then pour one beer into a glass and compare.

Beer experts recommend an inch or two of head. Highly carbonated wheats and some higher-hop beers will naturally have even more.

A big, frothy head helps release aroma and does it over time, making a beer taste better, longer. It also takes some of the carbon dioxide sharpness, bite and gas out of your beer for a better drinking experience, said Brian Owens, head brewer at O'Fallon Brewery.

Kuplent and others recommend holding the glass flat and pouring down the middle. Vary your pouring speed to determine how much agitation, and therefore head, results. Pour against the side a little more as the head fills up.

"Trickling down the side is for sissies and will result in a too-gassy beer with little aroma and poor, quickly dissipating head," writes Randy Mosher in his wonderful book "Tasting Beer" (Storey Publishing, 2009, $16.95).

There is a notable exception: bottle-conditioned beers, ones where the yeast continues to work its magic in the bottle and eventually settles to the bottom. These beers — many of them Belgian — must be poured slowly, probably down the side, to avoid dumping all that yeast into the glass, says Paul Hayden, manager of the Wine and Cheese Place in St. Louis.