Whether it's Hudson Valley foie gras or Kentucky Bibb lettuce, the best American food is decidedly local. The same goes for beer. Today the itinerant hophead faces a dizzying variety of choices, not least because what's on tap in Portland, Oregon, differs markedly from what's available in Portland, Maine.

I recently set out to find the 20 best craft breweries in America, a treacherous exercise considering that there are now more than 1,300 in the country. In assembling this list, I relied not only on years of committed consuming but also on the informed opinions of bartenders, "brewspaper" editors, beer writers and industry analysts. I scanned the results of 10 years worth of Great American Beer Festival judgings to see which breweries performed the most consistently in the annual competition. Holding the list to 20 meant leaving out some excellent breweries--and there are many. These days a world-class beer is often around the corner or in the next town over, waiting for you to find it.

Most of the following breweries are open to visitors and equipped with on-site brewpubs.