I am wondering if there are any commercial beers out there that use the sour mash technique. I have never personally used the technique in homebrewing, but I have heard it produces great results and requires little to no aging since the sourness is achieved during the mash rather than during fermentation. Since breweries are very fond of quick turnaround, I would assume that someone out there is using the technique for their sours. But maybe not. And if not, why not?