Starting around Memorial Day, beer aisles in supermarkets across the country undergo a seasonal metamorphosis — the invasion of the special summer brews!

Courtesy of the micro- and craft-beer revolution of recent years, American breweries, from nationally distributed names like Sam Adams to local crafters like Brooklyn Brewery, jump into the annual summer release fray.

For beer lovers, this expanding seasonal choice is a nice problem to have. But it begs some questions: What makes for a great summer brew? What traditions are behind these seasonals? And what foods work best with these beers?

Ideally, great summer beers should be crisp, refreshing, and food-friendly, with light to medium body and moderate alcohol, yet still be packed with aroma and flavor. Various beer types qualify, but the best summer "models" tend to hail from Germany and Belgium, two centers of brewing excellence. And for quality summer quaffing, no style outshines the wheat-based brews from these two beer-loving countries.