MADISON, Wis. (AP) – The federal government shutdown could leave America’s craft beer brewers with a serious hangover.  Stores will still offer plenty of suds. But the shutdown has closed an obscure agency that quietly approves new breweries, recipes and labels. That could create huge delays throughout the rapidly growing craft industry, whose customers expect a constant supply of inventive and seasonal beers.  The Alcohol and Tobacco Tax and Trade Bureau, or TTB, is a little-known arm of the Treasury Department. The agency will continue to process taxes from existing permit holders, but applications for anything new are in limbo.  Brewers say the agency already takes as long as 75 days to act on applications. The wait could grow longer because of the shutdown.