Among the tricks of the airline trade, one of the wiliest may be which wines carriers serve to premium international business-class passengers. Top sommeliers tout selections with breathless descriptions—even for the $9 bottles.

A price check on the wine menus of a dozen top international airlines uncorked a wide array of answers. A few pour expensive bottles, some even aged in airline cellars. Others serve lesser-known, inexpensive labels with dreamy descriptions and nary a whiff of the average retail price.

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