In the world of wine esoterica, lot 280 at Hart Davis Hart’s auction in Chicago earlier this month loomed large. It was a quintet of bottles from the first five vintages (1992–1996) of Colgin Cellars’s “Herb Lamb Vineyard,” a rare and highly prized Napa Valley cabernet sauvignon. But these were not just any bottles: They were melchiors, each holding 18 liters, or the equivalent of 24 regular wine bottles. A melchior weighs over 100 pounds, and several strong arms are required to grip and tilt the bottle when it is poured, or it can be supported by a specially designed sling. Hart Davis Hart’s catalog described the Colgin quintet as one of only two sets in existence. Its cover was illustrated with a close-up photo of one of the labels hand-notated with the numbers “2/2.” Lot 280 carried a stratospheric estimate between $400,000 and $600,000.

Unexpectedly, the melchiors were withdrawn from sale at the last minute. “One of the corks had sunk down into the bottle,” the president of the auction house, Paul Hart, said. Lot 280 was returned to its unidentified consignor, described as “one of the most prominent collectors in North America.” A chapter was closed, at least for now, on a curious tale.

From its inception, Colgin Cellars’s cabernet sauvignon has been one of Napa Valley’s most sought after wines — first made by the legendary Helen Turley and now by her protégé, Mark Aubert. The winery’s proprietor, Ann Colgin, is a fixture on the charity auction circuit. She is also the owner of the only other set of melchiors, as reported in Wine Spectator magazine two weeks ago. That set, unlike the one marked 2/2, has never left the winery.

Why had Ms. Colgin created such titanic bottles? “Colgin Cellars makes large format bottles each vintage primarily for charitable donations,” she said in an email. She declared her pride that those big bottles have raised over $3.5 million for charity. “I don’t really promote the fact that we even produce large formats like this because then people start calling and asking for us to do them,” Ms. Colgin wrote. “But I understand that rarity creates a big demand especially when the market is so strong.”

In a divorce settlement in 1997, Ms. Colgin’s former husband, Fred Schrader, got one of the two sets of melchiors. Ms. Colgin’s preference was that they not “slip into the commercial arena.” But Mr. Schrader sold the melchiors to the Rio casino and hotel in Las Vegas, then an aggressive acquirer of trophy wines. A few years ago, the Rio resold the melchiors to the current owner. A special set of shelves was built for them in the vast cellar beneath the owner’s mansion in a Southern state where, it is reported, one turns the corner only to see many more melchiors.

Because of the enormous volume of wine pressing against the cork when the bottles are on their sides, melchiors are prone to leakage. According to a reliable source, at least two of the melchiors did leak while in their Southern cellar. The situation may have been related to temperature swings of up to 10 degrees that occurred when the door to the outside was frequently opened during construction in the cellar. By the time of the Hart Davis Hart auction, the five melchiors were veterans of several moves around the country: California to Nevada to Georgia to Illinois. Discriminating collectors, for whom provenance is key to value, could not be happy with such a peripatetic history.

At the same auction at which the Colgin melchiors were to have been put on the block, a single melchior of Chateau Cheval Blanc 2000, a highly collectable millennium vintage of Bordeaux, was sold for $32,000. Even with their rarity, it is hard to imagine that the Colgin melchiors would have fetched the estimated price of between $80,000 and $120,000 a bottle, thereby dwarfing the price of Bordeaux royalty.

So rare are melchiors that several wine professionals who I queried had never heard of them. An exception was a wine writer and collector, Mark Golodetz, who had hands-on familiarity with the format, having once brought one back from Italy. “It was a melchior of Valentino Barolo 1978, one of the best of the vintage,” Mr. Golodetz said. “I bought a seat for it on the Alitalia flight home and buckled it in next to me. The ticket was in the name of Mr. Valentino.”

“Mr. Valentino” was actually opened and drunk by Mr. Golodetz and a large and lucky group in Canada. “It was a beautiful wine,” he said.

Will the Colgin melchiors also one day be opened? Not necessarily. “Most melchiors are bought for the ‘wow’ factor by collectors who’ve got to have not only the rarest but the biggest bottles,” a local sommelier said. “They have no intention of drinking them down. Anyway, at eight pours per bottle, a melchior provides 192 glasses of wine. Who gives a dinner party big enough for that?”