The august New York Times splashed a big story over its food pages this week, the big news being that you shouldn't use a great wine in cooking.
What a surprise.
The writer, Julia Moskin, seems to have deliberately set out to misunderstand the oft-repeated advice to "use a wine you would drink." She took that to mean a wine she liked, so she compared an oaky Chardonnay with a New Zealand Sauvignon Blanc, a California tawny Port with one from Portugal.
Actually, the idea is much less subtle. Basically, it's this: Cook with a simple wine that has no major flaws.
When you apply heat to wine, it burns off the subtleties that make a great wine great. The alcohol mostly volatilizes, to the point where you can't taste it any more if you cook the wine for more than a minute or two. Any subtleties, like the teeny amounts of aromatic esters that make a wine complex, will be gone.
What's left is the basic structure and dominant flavors. If the wine tastes primarily of cherries, you might get a hint of cherry flavor in the dish, depending on what else is in the pot. If the wine tastes excessively earthy, gamy, metallic or (heaven forfend) corky, that's what you get, so don't think you can salvage that corky bottle by cooking with it.
But mainly, you get whatever sweetness, acidity and tannins are there. If the wine is sweet, it's just like adding sugar to the recipe. Acidity is the main reason we use wine in a dish. It perks up flavors in the same way that a squeeze of lemon might. Good cooks know that this changes the balance of a dish, and make sure there is some sweetness to compensate, either in the form of onions and carrots or with the simple addition of a sprinkle of sugar. (My thanks to Madeleine Kamman for this invaluable piece of sage advice.)
You also get to keep all the tannins, which leads to the one useful admonition in the article. Because tannins remain in the finished dish, if you don't want the burr of that texture on your palate, don't use a tannic wine in cooking.
Tannic wines are good for marinating, however. When I was tasting regularly with Jim Laube, we knew that instinctively. One of his favorite catch phrases, applied to mediocre wines, often too tannic, that had no other major flaws, was, "Well, you can always soak a chicken in it."