First, the terminology: A corkage fee is what a restaurant charges for opening and serving a bottle of wine that a diner brings in. Corkage fees vary—I have heard of charges as low as $10 a bottle to as high as $50 at expensive restaurants. Even if a restaurant claims a corkage fee, it doesn’t always charge the diner.

I am a recovering BYO-er. I used to bring wine to a restaurant not because it was a special bottle, but simply because it was mine, sitting around and needing to be consumed with a nice meal. I never brought bad or cheap wine to a restaurant and usually called the restaurant beforehand to make sure it was OK, but I was also aware that I was saving money by bringing my own wine. Often, I was not charged a corkage fee—and if I was, my cost was still lower than if I’d ordered an equivalent bottle from the list. Then I married a wine director of a restaurant. For her, bringing something less than great (i.e., old, rare, and expensive) is anathema. I’ve slowly come around to her point of view.

David Rossoff, general manager at the very new, very hot Osteria Mozza in Los Angeles, says that guests bringing extreme amounts of wine is “all too frequent an occurrence.” I witnessed this on Mozza’s second night of business: Four diners arrived bearing 10 bottles of wine—all heavy on the Parker points. Rossoff first told the guests that he would open 2 of the 10 bottles; they bargained him up to 3 bottles of wine and a bottle of Champagne. “They didn’t expect to pay corkage fees,” says Rossoff, “just as they said they didn’t know the corkage policy of the restaurant and still showed up with almost a case of wine. It was simply arrogant, insensitive behavior.” When I talked to him that night, Rossoff was frustrated that he had no clear way to deal with the situation.

My wife frequently comes home with stories of regular customers who come in carrying wine. Some graciously pay corkage if charged, others resist, but it always makes for a difficult situation involving her conflict between appreciating repeat diners by lifting corkage fees and meeting her restaurant’s bottom line every month.

I had a theory that wine subsidizes food costs to a degree; the true product and labor cost of a grilled grass-fed rib-eye steak with a chanterelle reduction, garlic mashed potatoes, and sautéed spinach might not be much lower than the $25 asking price, leaving little room for profit. Rubicon sommelier Lawrence Stone, however, disagreed. “Wine does not subsidize the food,” he says. “Wine should subsidize wine.” He listed all the costs that go into a good restaurant’s wine program: the salaries of one or sometimes two sommeliers, the high cost of quality glassware and its maintenance, the storage costs of carrying a large inventory of wine, the time and personnel required for good wine service. “Wine is not the biggest profit center for a restaurant; liquor is,” says Stone. “But you don’t see people bringing in their own bottle of gin and complaining about the cost of a $9 martini. ... I don’t believe in wine price gouging at restaurants. But people must appreciate what they’re paying for at a restaurant.”

To bring wine into a fine restaurant is to ignore the effort and work that’s gone into crafting a wine list that matches the food being served. Many restaurants allow you to bring your own wine anyway; but in return they charge you a fee.

I rarely bring my own wine anymore. If I do, I make sure it’s a special bottle that’s not on the list. I buy a bottle of Champagne or an apéritif white from the restaurant’s list. I share my bottle with the sommelier. And, if asked to pay a corkage fee, I don’t complain. As one of the letter writers in the San Francisco Chronicle put it: “We must also remember that our fantastic restaurant industry here would not survive on the profits made on just food. ... Bringing your own wine is a privilege, not a right!”