Hops, skip & a Jump : the regional uniqueness of beer styles

Perhaps more than any other product, beer evokes the place it was made. Weißbier and Germany, dubbels and Belgium, and most of all, Guinness and Ireland. Part of what makes these beers so memorable is what sets them apart and gives them their "taste of place." Many studies have tried to place that taste, and due to a lack of detailed data, have relied largely on qualitative methods to do so. We introduce a novel data set of regionalized beer recipes, styles, and ingredients collected from a homebrewing website. We then turn to the methods of evolutionary economic geography to create regional ingredient networks for recipes within a style of beer, and identify which ingredients are most important to certain styles. Along with identifying these keystone ingredients, we calculate a style's resiliency or reliance on one particular ingredient. We compare this resiliency within similar styles in different regions and across different styles in the same region to isolate the effects of region on ingredient choice. We find that while almost all beer styles have only a handful of key ingredients, some styles are more resilient than others due to readily available substitute ingredients in their region.