I truly appreciate a good brew every now and then, so I wore a big smile on my face this morning when I saw shares of Boston Beer (SAM 1.60%) trading up more than 13%. So what has everyone so excited?

In short, the company annihilated earnings expectations with their solid second-quarter earnings report.

Specifically, the creator of the wildly popular Samuel Adams brand turned in second-quarter net revenue of $181.3 million, an increase of 23% from the same year-ago period, and primarily due to core shipment growth of 21%. Meanwhile, net income nearly tripled to $1.45 per diluted share, up from $0.39 per diluted share in the second quarter of 2012.

For those of you keeping track, those numbers easily outpaced analysts' expectations for earnings of $1.34 per share on sales of $175.4 million.

Some background
For some context, remember Boston Beer stock fell by as much as 11% after the company reported disappointing first-quarter earnings in May, largely thanks to "slight softness" in Samuel Adams sales after its Spring seasonal program failed to meet expectations.

As I wrote at the time, however, Boston Beer was looking forward to better days ahead and had already completed the conversion to its popular Summer Ale in most markets.

Even so, while everybody had high hopes for Boston Beer's Summer offerings -- especially considering they would be offered for the very first time in the company's unique new can -- Koch himself admitted they were experiencing "increased competitive activities from both domestic specialty and craft beer brands that have made it challenging to grow Samuel Adams as fast as [they] would like."

Of course, that was a less-than-subtle reference to brewing behemoths like Anheuser-Busch InBev (BUD 1.26%), which happily owns more than a third of Craft Brew Alliance (BREW). Craft Brew Alliance, in turn, was formed just a few years ago through the merger of the Red Hook, Widmer Brothers, and Kona Brewing Companies.

Of course, as I wrote just a few weeks ago, the folks at Red Hook in particular have been busy winning business from the likes of beer-selling extraordinaire Buffalo Wild Wings (NASDAQ: BWLD), with whom they collaboratively created the wing specialist's Game Changer Ale to cater to the beer-loving sports bar crowd.

So, with all that frothy competition swirling around them, what led to Boston Beer's outperformance this time around?

Mmmmm....Summer beer
According to CEO Jim Koch, if we're wondering where they found strength this quarter, look no further than the solid performance from the company's seasonal program.

As it turns out, American consumers really do enjoy a good Summer brew, and Boston Beer was more than happy to oblige. And if you can't tell from the video below, this guy seriously appreciates everything that goes into his products. 

Additionally, Koch says, Boston Beer's flagship Samuel Adams Boston Lager made an impressive comeback from last quarter's stagnant sales as well.

As a result, depletions -- an industry measure for how fast the products travel from warehouses to consumer outlets -- grew a whopping 24% from the same 13-week period last year, allowing the company to increase its full-year 2013 depletions growth guidance to between 17% and 22%, up from their previous estimate of 10% to 15%.

Better yet, even though Boston Beer lowered their full-year gross margin target to between 52% and 54% (down from 53% and 55% before) thanks mostly to increased cost of ingredients, the company still raised its earnings guidance to between $5.10 and $5.40 per share. Remember, that's a significant improvement from the previous guidance for earnings of between $4.70 and $5.10 per share.

Are you thirsty yet?
In the end, I'm still positively impressed by how well this up-and-coming brewer is handling the ongoing assault from its strong competitors, so I'm not surprised in the least that this great quarter pushed shares of Boston Beer to a new all-time high.

I've said it before and I'll say it again: Boston Beer stock may look expensive on the surface, but it remains one of the most Foolish (with a capital "F") companies I know. Even from today's lofty levels, then, I'm convinced shareholders can look forward to handsome gains for years to come.