What’s on Tap?
For oenophiles, a key question is what wines the machines contain. Do they beat out the usual minibar fare?

Well, pretty much. At La Confidante, the Plum in every room dispenses Evesham Wood Pinot Noir from Oregon ($5.25 for a 2-ounce glass; 5 oz. for $16) and Justin Sauvignon Blanc ($4, $12) from Paso Robles. While these are attractive, well-chosen wines, they’re hardly what I’d call special. In retail shops, the crisp, citrus-y sauvignon blanc costs a mere $14. The Evesham Wood pinot is spicy and perfumed, a decent bottle at $26. Still, it’s instant gratification—and for guests in the Penthouse and Miranda suites, unlimited glasses will be free during stays until April 30.

The Four Seasons Silicon Valley wines are a step up in quality and price. Both are Napa stars: bright, elegant Newton Unfiltered chardonnay ($40 retail) and vibrant, distinctive Chappellet cabernet sauvignon ($60 retail), with per-glass Plum prices ranging from $14 to $18.

Rosewood Sand Hill offers two equally compelling Napa wines: the creamy, lush 2016 Far Niente chardonnay ($55 retail) and the plummy, savory 2013 Groth cabernet sauvignon ($52 retail). Choices will typically change every three months or so.

But since it’s so easy to swap out wine bottles in the Plum, these standard-level wines don’t have to be your only choices. Florian Riedel explains, “When guests stay frequently, we usually know about their wine preferences and can choose something to surprise them.” Nice. For an additional charge, you can let the hotel know what you want to drink while you’re in residence. Very nice!

The Future of In-Room Wine
Many hotels will, no doubt, follow suit. “Hotel 2020: The Personalization Paradox,” a report published 18 months ago by IBM Global Business Services, said personalizing a guest’s experience is what will help the industry survive in the face of existential threats such as Airbnb.

And the Plum seems perfectly timed, as the minibar has become a flop for many hotels. From 2007 to 2012, according to PKF Hospitality Research Inc., hotel revenue from minibars dropped 28 percent. Insane prices for poor quality is the reason many shun the wines. (There are such exceptions as Aspen, Colo.’s the Little Nell, where one might find a Domaine Dujac Burgundy.) Minibars are a hassle for hotels, too. Employing human beings people to check and restock them daily is very expensive.

The Plum, on the other hand, automatically keeps track of how many glasses you drink, adds the cost to your hotel bill, and even notifies management when it’s time to replace the bottles.

It also fits neatly into the current tech-savvy hotel room trend. “Technology,” says Koretz, “is forcing hoteliers to rethink what service means in an era where they may never interact with the guest in person.”

So far, the in-room Plum’s biggest problem is awareness. As guests checked out at the Four Seasons, some were asked why they hadn’t tried a glass of wine from the machine. They replied that they had thought it was an air purifier.