My regard for Walnut Creek, CA's CALICRAFT BREWING increases exponentially with each new beer of theirs I try. I looked at my reviews of each of their beers, and not one's been under an 8/10. Already a bold, badass 8.7% brown ale, they went and barreled their "OAKTOWN BROWN" in an effort to soup it up even more. The result is this super-limited bottle I found at Whole Foods (!) called "RUM BARREL OAKTOWN BROWN SOUR", which didn't even get its own new label, and instead merely was graced with stickers plopped over the main bottle to signal its differences from the main product.
The reminds me of another "good", albeit relatively normal beer that was made into something otherworldly via the aging process - Devil's Canyon's bourbon barrel-aged version of their "Full Boar" scotch ale. We reviewed that one here. For Calicraft's, the rum barrel wrings a great sweetness out of this brown ale, and makes it quite creamy, with dominant tastes of wheat, molasses, vanilla and a real earthy sourness. The roasted backbone is there, but no discernible bitterness. Approachably sour - not tart, not puckering, just phenomenal. 9/10.