In the 1980s, as the rye business was drying up and all of the rye whiskey distilleries in Pennsylvania and Maryland were closing, what little remaining rye whiskey production there was shifted to Kentucky. The Kentucky distilleries had always made rye whiskey, but when the last of the Maryland and Pennsylvania concerns closed down, only Kentucky remained. Although venerable brand names like Old Overholt, Pikesville, Rittenhouse and Mount Vernon continued to be sold, the whiskey was coming from Kentucky.
Now the same thing is happening with brandy.
Well, not exactly the same thing.
Brown-Forman has long owned Korbel. Heaven Hill owns Christian Brothers and Barton owns Paul Masson. Of the four best-selling U.S.-made brandies only one, Gallo's E&J, is not closely linked to a bourbon producer. All four companies use California grapes and the distilleries are there too. Gallo and Korbel also do their aging there, Korbel in used Jack Daniel's barrels.
Heaven Hill and Barton both ship their new-make brandy to Kentucky, enter it in used bourbon barrels there, and age it in their Kentucky warehouses. Both use warehouse locations for brandy that they prefer not to use for bourbon, specifically the lower floors of Barton's warehouses, and Heaven Hill's brick warehouses in Louisville. Most of the brandy is bottled and sold after two years of aging.