With tens of thousands of visitors soaking up Bostonian culture while in town for the Democratic National Convention, shareholders of Boston Beer Co. (NYSE:SAM) are hoping that many decide to sample the local lager -- Sam Adams Boston Lager. Of course, if they prefer Sam Adams Light, Sam Adams Cherry Wheat, or perhaps a seasonal such as the Summer Ale, that's fine too.

Apparently, investors already have reason to smile; the market greeted Boston Beer's second-quarter numbers enthusiastically yesterday, sending shares 6.2% higher. Earnings soared 85% to $0.37, easily topping both the $0.20 earned last year and analysts' expectations for $0.26. Through the first six months, net sales have risen 5% to $106.7 million, driven by both a 4.3% rise in volume (to 626,000 barrels) and a modest price increase.

Seasonal beers and the flagship Boston Lager brand have been flying off retailers' shelves lately, but Sam Adams Light's persistent weakness remains a concern. There was already fierce competition in the low-calorie market segment from the likes of SABMiller's Lite and Anheuser-Busch's (NYSE:BUD) ubiquitous Bud Light, even before the advent of low-carb beers such as Coors Brewing's (NYSE:RKY) Aspen Edge.

Though the Coors-Miller-Budweiser beer triumvirate constitutes more than three-fourths of the domestic beer market, Boston Beer competes more directly in the premium aisle with imports and other handcrafted beer marketed by regional breweries such as Pyramid (NASDAQ:PMID), Redhook Ale Brewery (NYSE:HOOK) and hundreds of privately held microbrewers. Boston Beer is the best of class in this group, with superior revenues, earnings, volume, and margins.

Boston Beer may not have the distribution capabilities, advertising budget, or name-brand recognition of the three titans, but as the largest craft brewer in the country, the firm does have several things in its favor. Its beer, for one, is widely acclaimed for its quality and flavor and has been recognized internationally with more than 650 awards (many are proudly displayed at the firm's Boston headquarters). The company's balance sheet also deserves mention. With more than $55 million in cash and zero debt, it's as clean and clear as one of the company's signature brews.

On a macro-level, all brewers, big and small, have to contend with a stagnant domestic beer market and per-capita consumption that is on the decline. Thus Boston Beer's future growth is largely dependent on the ability to cultivate a larger following outside its loyal fan base. The company may well make some progress in capturing market share, a challenging prospect. However, aside from the firm's enticing enterprise value/free cash flow ratio of 10.5, valuation metrics suggest even thirsty investors wait until Happy Hour to purchase the stock.

Fool contributor Nathan Slaughter prefers to focus his research efforts on the Sam Adams Pale Ale. He owns none of the companies mentioned.