27 CFR §5.146

1. (a)The class blended applejack. “Blended applejack” is a mixture containing at least 20 percent on a proof gallon basis of apple brandy (applejack) that has been stored in oak barrels for not less than 2 years, and not more than 80 percent of neutral spirits on a proof gallon basis. Blended applejack must be bottled at not less than 40 percent alcohol by volume (80° proof).
2. (b)Label designation. The label designation for blended applejack may be “blended applejack” or “applejack-a blend.”