If you're putting up a bumper crop of tomatoes, or even just making a huge pot of sauce with them, well, first of all, I envy you. (Alas—our tomato plants got swamped with rain this summer and whatever fruit didn't rot on the vine was carried away by rodents. Such is urban farming.) But if you—or the farmers at your local market—were more fortunate with your tomato harvest this year, you're probably dreading the time you'll have to spend blanching, chilling, and peeling all those pounds of tomatoes before cooking or canning them. Is this step even necessary?
Why would you peel tomatoes?
The tomato skin is a different texture from the tomato flesh, and will remain so in sauces and purées—you'll get tiny chunks of skin instead of an uniformly smooth mixture. Moreover, the tomato skin is heavy in a kind of nutrient called flavonols, which impart a bitter flavor. (More on this below.) Whether either of these conditions bothers you or not is entirely your thing. If you want to go by the book, a few questions to guide you: Do you hope these tomatoes will resemble something like a sauce when everything is through? Then you probably want to peel them. Same goes if you're canning tomatoes for a later time, when they'll probably be turned into a sauce. Though it's completely a matter of preference, for the smoothest, mellowest sauce, you might consider peeling.
Why wouldn't you peel tomatoes?
Obviously there's no reason to peel tomatoes that are going into something like a salad, or sliced onto a grilled cheese sandwich: the skin is what helps everything hang together. Ditto tomatoes you're slow-roasting in the oven; if you remove the skin they'll just melt away.
But regardless of how you're preparing them, there's another reason you might not want to peel your tomatoes: those flavonols we mentioned. They're a kind of plant-based antioxidant and, as mentioned earlier, like other plants that are good for you, they impart a bitter flavor. But studies have linked flavonols with lower risk of cancer, cardiovascular disease, and other age-related complications, and you won't get much of them if you peel your tomatoes—up to 98 percent of flavonols found in tomatoes were found in the skin. So keeping your tomato intact will maximize its nutritional value to you. (Alternately you can save the skin for later use.)
Oh, and also: peeling tomatoes is sort of annoying. But if you must...
How do you peel tomatoes?
Well—the process doesn't have to be that fussy, actually. All you do is this: Bring a pot of water to a boil. Fill a bowl with ice water. With a sharp knife, score each tomato on the bottom (that is, not the stem end), making an X. Drop tomatoes into boiling water and cook for 1 minute before removing with a slotted spoon and plunging immediately into the ice water to stop the cooking. The skin should slide right off. And if not, well, it might even do you some good.
