Airlines wine in the sky Cabin cru: Cathay Pacific stewardesses proffer the airline's latest reds Wines are affected by pressurized, drier cabin air on planes Bitterness and tannins are accentuated, fruit flavors diminished United Airlines goes through 7 million bottles of wine each year Good wines on board reflect the premium brand airlines want to present (CNN) -- Roy Moorfield and Lau Chi-sun are in charge of one of Cathay Pacific's most rigorous selection processes. Last week 140 candidates were brought before them and evaluated by appearance, body, character and even how bitter they are. "Any flaws or problems here on the ground just get magnified in the air," said Moorfield in knowing tones. While it may sound like the way stewardesses were selected some 40 years ago, Moorfield and Lau were actually in Hong Kong to pick out new additions for the airline's wine selection. It's a job that's kept Moorfield busy for over 24 years as a consultant for the airline. "It's a dark and lonely life," he quipped, "but someone has to do it." Each year around 3,000 glasses of wine are checked by the pair's educated palates, and through blind tastings with other connoisseurs they decide what vintages will thrive at 35,000 feet and appeal to discerning drinkers in each travel class. Tannins and bitter tones in wines are exacerbated by dry cabin air and some wines don't fare well with the vibrations from air travel and become "bottle shocked," the experts say. It's often the delicate fruit tones that add a depth and richness to wines that are first to take a hit. Any flaws or problems here on the ground just get magnified in the air. Roy Moorfield, wine consultant White wines don't have such a problem, says Moorfield, and if you like the taste of a champagne on the ground it's more than likely to taste just as good in the air (regardless of how much you drink). Since reds are more delicate and sensitive to flight, Moorfield admits that the Economy Class offerings can't compare with a glass at a wine-buff's dinner party. However what those in First and Business Class are still some of the best around. Cathay's new line-up includes a selection of Grand Cru from some of the most renowned vineyards in the Saint-Emilion. Read more: How airlines stand out from the competition The airline uncorked (or unscrewed for those in Economy) around 1.5 million bottles last year. For United, one of the world's largest airlines, that figure is more like 7 million bottles, according to the airline. As well as taking a sizable chunk of an airline's inflight catering budget, wines also contributes a large part to an airline's image, particularly among premium passengers. Wines are increasingly "critical" to the way an airline is perceived, believes James Ginns, Cathay Pacific's General Manger of Inflight Services. "People expect very good wines onboard," he said, highlighting growing interest in wine in China and the enduring popularity of wines from France's Bordeaux region. All in the nose: Lau Chi-sun and Roy Moorfield, Cathay Pacific's wine consultants For vineyards, being chosen as a First and Business Class selection is also good business. "Wineries see the first class cabin as a really sexy place to be, as a place where they want their labels to be seen," said Doug Frost, master sommelier for United Airlines. Read more: Upcycling old aircraft For those who don't get to taste the good stuff in the cabins at the front of the plane, Frost suggests a few tips when making a choice (if there is one) in economy cabins. "The new world wines with their jammier fruits show a little bit better than older world wines, but that's painting with a broad brush and ultimately it depends on personal tastes," he says. Moorfield echoes that, eschewing any notions of wine snobbery: "It doesn't matter what it is; you either like it or you don't." Cathay's cabin crew are given tasting lessons by Moorfield and Lau so they can recommend wines with particular foods served on board, but they're absolutely forbidden from sampling the wine while flying or taking any opened bottles home at the end of a flight. So what does happen to all those opened bottles when inflight service ends? Oenophiles, get ready for a different kind of "bottle shock." "They get poured away," says Ginns. It's to makes sure they don't reappear on board and get served by mistake.