Playing off superstition regarding the number 13, this August The Boston Beer Co. is introducing Samuel Adams Thirteenth Hour, referring to the beer’s mysterious combination of flavors and 13 brewing ingredients, the company says. Samuel Adams Thirteenth Hour combines the roasted chocolate and coffee flavors of a traditional Belgian stout with the spicy character of an oak-aged ale, it adds. Part of the Samuel Adams Barrel Room Collection, Thirteenth Hour is aged in Eastern European oak barrels originally used to age brandy in Italy, which impart a subtle, sweet and toasty note to the beer, the company says. The brew is packaged in a 750-ml. bottle with a champagne cork closure and retails for $9.99 each bottle.