In the early days of whiskey production, a tax was levied on whiskey as soon as it left the still. Because bourbon improved through aging, distilleries convinced the government that the tax should not fall due until the maturation process had ended. The government relented and gave distilleries two years before the tax would fall due. If, at the end of two years, the distilleries did not have a customer for the whiskey, they had to pay the tax. At that point the bourbon was removed from the bonded warehouse and stored in the free house, so named because the whiskey was then free of tax.