Pop open the can, raise toward face, open mouth, pour contents down throat - it's a straightforward challenge best undertaken, according to the beer commercials, with the able assistance of two or three girls in bikinis.

A more meaningful, possibly less-debauched experience awaits the reader of Randy Mosher's new "Tasting Beer: An Insider's Guide to the World's Greatest Drink" (Storey Publishing, $16.95).

Mosher is one of America's leading beer authorities, an instructor at the Siebel Institute of Technology and World Brewing Academy in Chicago. Visit almost any brewery in America, and you'll find a well-thumbed copy of his essential recipe guide, "Radical Brewing" (Brewers Publications, 2004).

Mosher doesn't pretend that many, many people - probably the majority - don't really care about the taste of their beer. Advertising, price and brand loyalty have more to do with the sixpacks they choose to stack in the refrigerator than idiosyncrasies of flavor.

"Some people just want to drink for refreshment, and that's fine," he said in a recent phone conversation. "But others want to discover the sensual, the sensuous, the intellectual pleasure of taste."

The key to reaching that pleasure is understanding how each particular beer was made.

"With wine, you go back to the vineyard where the grapes were grown, to see the soil, to find out which side of the mountain they were grown on," he said. But with beer, you've only got four basic ingredients: water, malt, hops and yeast. So "it's all about the brewing process."

Some passages of "Tasting Beer" are utterly wonkish, including an exacting section on the vocabulary of beer flavor. Forget about "tastes great, less filling" - is your beer "goaty" or "autolysed"?

That Band-Aid flavor you sensed in a glass of pale ale? Mosher writes that it's chlorophenol, the unsavory product of poor rinsing of the chlorine used during sanitation.

Maybe you won't care about the book's guidelines on the dissolved carbon dioxide level of a Bavarian hefeweizen (3.5-4.5 volumes), but anyone who's ever suffered a dreaded foam-over will learn the proper way to pour that famously fizzy wheat beer. ("Boldly down the center of an absolutely clean glass.")

Sure, you can impress your friends with your ability to detect the difference between ethyl and fusol alcohol. But more importantly, if your stout tastes sour, if a pilsner looks cloudy, if your India pale ale smells like buttered popcorn (that's diacetyl, the product of bad yeast or dirty tap lines), Mosher urges you to use your newfound knowledge to confidently "send it back!"

The serious beer geek will appreciate the advice on presenting beer for professionally judged events. The casual beer drinker can skip that and head straight for Mosher's tips on hosting a tasting. (Hint: Use nice, clear glassware, not plastic cups.)

Even those stuck on BudMillerCoors will find themselves learning to appreciate the subtle qualities of their golden quaff. Take a walk in the fresh air, Mosher suggests, "and really pay attention to how smells change from location to location. I think half of tasting skill is just being able to concentrate."

And ignore those advertising claims:

"Rocky Mountain water" doesn't improve flavor because all modern breweries treat their water to make it suitable for their beer. "Cold filtering" has only a very subtle impact on flavor, while beechwood aging - "a nice nod to tradition" - has none.

But what about those bikini-clad girls?

"It's staggering," Mosher writes, "that in this day and age, there are still enough people vulnerable to this fantasy . . . especially when the supposed love potion is bland, mainstream beer." *

"Joe Sixpack" by Don Russell appears weekly in Big Fat Friday. For more on the beer scene in Philly and beyond, visit www.joesixpack.net. Send e-mail to joesixpack@phillynews.com.