The musician has been friends with Full Tilt’s founders — Fertig and Dan Baumiller — since before the business began brewing out of Peabody Heights Brewery in the Abell neighborhood of Baltimore six years ago, Gaskarth and Fertig said. They met through Gaskarth’s brother-in-law at a weekly Monday night beer tasting, during which a group of friends would gather and, among other things, taste Fertig’s home-brews.