When sommelier Sam Mushman started curating his wine program at Arthouse Hotel in NYC, he aimed to assemble a generous half-bottle selection. Mushman favors the smaller serving vessel because he believes it gives consumers the chance to sample some of the world’s finest wines at (relatively) affordable prices.

Unfortunately, half-bottles are not as prolific on distributor lists as they once were, Mushman says, and assembling a good selection was a difficult undertaking. “Out of all the great wines you might want to consider adding to your list, probably one out of every 10 of those offers 375-milliliter bottles,” he says.

His current list includes half-bottles of Mayacamas Chardonnay for $75, a 2011 Azelia Barolo for $56, and a 2012 Brusquières Châteauneuf-du-Pape for $64. Following a lot of positive feedback, he now plans to expand the half-bottle list to include wines from lesser-known “secondary” regions.

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Half-bottles hold 375 milliliters, or 12.6 ounces, of wine — the equivalent of two generous glasses. Despite Mushman’s best efforts in NYC, overall, sales of this format are declining. Still, most industry professionals agree half-bottles offer numerous advantages, especially for high-end and aged wines.

Consumers who want to splurge might not have the financial means to spend, say, $200 on a bottle of Caymus, but they might be willing to pay $100 on a half-bottle. The smaller serving size also offers the perfect solution when figuring out a wine pairing for a seafood appetizer and red meat entree: half a bottle of white and half a bottle of red.

Another advantage to half-bottles is something that’s often thought of as being a drawback. Wines age faster in the smaller format because a higher proportion of the liquid comes in contact with oxygen. It’s not necessarily desirable for most white wines or Champagne, but when it comes to burly, tannic reds, like Napa Cab or Barolo, faster aging means wines are approachable at a much younger age. (Mushman says the 2011 Barolo on his list “tastes like it’s been aging for at least three to five years longer than it has been.”)

Jason Haas, partner and general manager at Paso Robles winery Tablas Creek Vineyard, is a self-professed half-bottle enthusiast, both as a consumer and also as someone working in the industry. He says half-bottles are “an incredibly customer-friendly way to offer wines and [they] generally offer higher quality than wines by the glass.”

“There tends to be very good visibility on wine lists as half-bottle sections are smaller and they’re usually at the front of the book,” Haas says. “If we can get good customer loyalty out of that, then that’s wonderful.”

Ridge Vineyards in the Santa Cruz Mountains offers four of its wines in half-bottles. The winery sells them to wholesale markets and direct to consumers through its wine club and at the winery itself. “It gives us the flexibility for people looking to have a glass of wine on the property without having to offer wine by the glass,” says Ryan Moore, vice president of consumer sales.

One of Ridge’s wines, a Cabernet Sauvignon-driven blend called Monte Bello, is famous for its inclusion in the 1976 Judgement of Paris tasting. Ridge offers this wine as part of a futures wine club in both 375- and 750-milliliter formats. Because the wine can take years to mature, Moore says, a lot of savvy wine club members include half a dozen half-bottles in their orders so they can drink the wine sooner and gauge its evolution.

Despite all these advantages, half-bottle sales are indeed declining. For many years, Tablas Creek has offered its two flagship wines, Esprit de Tablas and Esprit de Tablas Blanc, in 375-milliliter format. But sales have dropped 80 percent over the past decade, and the winery is at a crossroads. “We’re going to bottle them in half-bottles this year, but I’m not sure we will next year,” Haas says.

Many in the industry point to Coravin, the space-age pour-and-preserve technology, as one of the reasons for the downturn. Coravin lets users pour individual glasses without opening the bottle, allowing them to (theoretically) revisit the wine over time and enjoy its evolution. For restaurants and wine bars, this provides a chance to sell high-end wines by the glass without the pressure of selling the whole bottle before it turns to vinegar.

“There’s a lot of pros to the Coravin system, but there are also cons,” Mushman says. “It doesn’t keep wine good for six months, it keeps wine good for a few weeks, and that’s only if the cork holds up and if the [inert argon gas dispensed by] Coravin does its job.”

The half-bottle, on the other hand, takes those variables out of the equation and offers guests the same romantic experience that comes with serving a 750-milliliter bottle. “From the point of opening the bottle, to smelling the cork, tasting the wine, and watching the wine develop over 10 to 20 minutes — that’s your bottle,” Mushman says.

New York-based importer and distributor Skurnik Wines currently offers more than 100 dry 375-milliliter bottlings. (Mushman cites it as one of the best sources for his half-bottle list.) The company’s chief sales officer, Jonathan Schwartz, says half-bottle sales peaked in 2012 or 2013, following the proliferation of tasting menus in New York City. He agrees that Coravin, and its suitability for tasting menus, is “probably the driving force behind the discontinuation of the 375-milliliter bottle.”

Others say distributors should also shoulder some of the blame for declining sales. “There are fewer distributors that want to stock half-bottles and within the ones that do, I think they’re generally not working as hard to sell them,” Haas says. This might be because fewer restaurants have extensive half-bottle selections, but could also be due to the superior profits 750-milliliter bottles offer.

“It costs just as much for [distributors] to deliver a case of half-bottles as it does to deliver a case of full bottles. It’s an extra item to stock in their warehouse, and they’re making half as much money on it,” he says. And if those 750-milliliter bottles are destined for a by-the-glass program, there’s also the inherent waste to consider. This may, in turn, drive more sales.

Additionally, half-bottles are expensive for wineries because, despite containing half the amount of wine, they still require a bottle, a capsule, a cork, and a label. And with each of these items sourced in smaller lots — those wineries that do offer half-bottles do so in much smaller volume — they’re much more expensive per unit.

“Ultimately, it ends up costing between two-thirds and three-quarters of the cost of your full bottle,” Haas says. “In the market, it’s basically not viable unless you subsidize to something only slightly more than half the price of your full bottle, so the winery generally eats that extra cost.”

Though somewhat against the wishes of his cellar team, Haas wants to continue half-bottle production for as long as possible. But the category is at an impasse, with each step of the supply chain pulled in multiple directions.

If drinkers want to continue reaping the benefits of half-bottles, only one thing will persuade wineries and distributors to take a hit on profits: consumer demand. Otherwise, the days of the half-bottle are numbered.