What Is the Microbrew Capital of the United States?

In a decision sure to stir controversy - as well as the occasional bar room brawl - Santa Rosa, CA - the county seat of the wine-growing Sonoma region, was ranked as the premier microbrewing capital of the US.

As a public service for understandably concerned citizens, the Low-Down has also included a map and listing of the Top 50 craft breweries compiled by the US Brewers Association so that discerning data analysts can compare the two from a statistical, geographical and gustatory standpoint. We will leave the semantic and religious differences between 'craft' and 'microbrew' to the experts. JL

Alyssa Pereira reports in SFGate and Russell Goldenberg in The Pudding:

A visual data website scoured data from RateBeer.com, a beer rating site, as well as census and map information, and deduced the city with with the best micro brewing culture in the United States: Santa Rosa, California. Santa Rosa beat out beer hubs as San Diego, Denver, Portland, and Chicago. An area's ranking is weighted 80% on "quality" and a 20% on "quantity" (which lands Santa Rosa at the top of the list). Adding more weight to the "quantity" field drops Santa Rosa down the list.
While many other U.S. metropolitan regions might be known as more obvious beer meccas than the greater San Francisco Bay Area, there's one section of the craft beer landscape where one of our cities apparently thrives: microbreweries.
A researcher named Russell Goldenberg with a visual data website called The Pudding scoured some data from RateBeer.com, a beer rating site, as well as census and map information, and deduced the city with with the best microbrewing culture in the United States: Santa Rosa, California. Santa Rosa beat out such high profile beer hubs as San Diego, Denver, Portland, and Chicago, primarily due to the quality of Santa Rosa area breweries Russian River Brewing, Bear Republic Brewing Co., Shady Oak Barrel House, Moonlight Brewing Company and Cooperage Brewing Company, as scored by RateBeer.com users.
Goldenberg notes that the findings might seem subjective because an area's ranking is weighted 80 percent on "quality" and a 20 percent on "quantity" (which lands Santa Rosa at the top of the list), but a user who values diverse brewery options can change that by adding more weight to the "quantity" field (which drops Santa Rosa down the list).Goldenberg's map below.

There is one thing to note for staunch craft beer advocates: the breweries highlighted in Goldenberg's data aren't necessarily "microbreweries," at least according to the definition put forth by the Brewers Association. The BA, on their site, defines a microbrewery as one that that produces "less than 15,000 barrels of beer per year with 75 percent or more of its beer sold off-site." Absent from the BA's list of U.S. microbreweries is Healdsburg's Bear Republic, cited in Goldenberg's study. (Russian River, also noted in Goldenberg's study, may also now be too large to be considered "micro.")
Nevertheless, the premise of the project is fun, with the user able to adjust the weight of the data to see where their ideal beer city is.