It pays to be picky with vegetables says cooking guru Harold McGee.
‘Vegetables aren’t sweet and soft and easy to love the way fruits are. It takes a cook to make tubers, stalks, and leaves lovable. That’s because plants not only didn’t design them to be delicious as they did fruits, many tried to protect them by making them really unpleasant.
The flavours of most vegetables – and the fresh herbs that we use to add flavour to dishes – are actually there to serve chemical warnings and weapons and deter insects and other creatures from eating them. This is more obvious for such strong flavoured foods as garlic and onions and their relatives, bitter chicories, mustard greens and radishes and the other members of the cabbage family, and chillis. But even “green” flavours of lettuces and spinach and artichokes, and the earthy aromas of mushrooms and beets, come from chemicals that irritate and repel. We can enjoy all these foods because cooking alters and disarms or disguises their weaponry, or in the case of herbs, because we eat them in small quantities as accents rather than the main course.
Apart from seed-carrying fruits that we treat as vegetables, notably the tomato, most vegetables don’t ripen the way fruits do. They’re edible when they are a freshly sprouted seed and remain edible until they’ve become too fibrous to chew. Much of the produce we see in markets. Farmers’ markets included, has been harvested late in its edible life, for maximum mass and durability. Until I had a chance to grow some vegetables myself and chew on them every day or two through the season, I hadn’t noticed that big romaine (cos) lettuce leaves often taste rubbery, or realized how unlike their usual oversize versions midsize chard and collards are, tender and mild after just a few minutes of cooking.’
McGee goes on to say that when shopping for vegetables and herbs, remember that ‘Fresh vegetables and herbs are alive and breathing, and any that grow above the ground should look like it. (Root vegetables and onions look dormant and are.) The best quality fresh vegetables are the most recently harvested and most carefully handled.
Extra-large vegetables are usually the most mature and can be coarse in texture and flavor; tiny “baby” or “micro” vegetables are immature, mild in flavour and expensive. Choose vegetables and herbs with deep colours, a firm, full appearance, and freshly cut stems. Avoid vegetables that look dull, wrinkled, dented, bruised, slimy, mouldy; or that have brown, dry cut stems, or that have started to sprout. At farmers’ markets, avoid vegetables that have been sitting in the sun and are hot to the touch.
Precut vegetables are convenient but more vulnerable to spoilage than intact vegetables, and are often wilted. Refresh them in ice-cold water before using.
Frozen vegetables can equal or better the quality of fresh, especially vegetables that lose flavor and tenderness rapidly after harvest. These include green peas, and lima beans and sweet corn. Choose packages of frozen vegetables from the coldest corners of the market freezer, and just before you check out. Bag frozen foods together, and transport them home in a cooler. Repeated thawing and refreezing damages the quality of frozen foods.’
Harold McGee writes about the science of food and cooking: where our foods come from, what they are and what they're made of, and how cooking transforms them. On this site you can find out more about him, his books and his column in the New York Times.