How Green is your Bean? Or, How Color Teaches Us How to Cook

How Green is your Bean? Or, How Color Teaches Us How to CookI was preparing a tomato sauce with seafood and linguine this week. Once the water was boiling and I tossed the pasta into the pot, I turned to my last step in the preparation, adding the seafood to the simmering sauce, now fragrant with garlic and fresh herbs from my garden and even half a fennel bulb I’d sliced and sautéed with the onions. I had a small pile of bay scallops, some rings of calamari and about half a dozen shrimp. Once they hit the sauce and I stirred them in, I covered the pot and waited. What was I waiting for? For the shrimp to turn from steel gray to peachy pink, and for the calamari and scallops to transition from opaque to a pure white.

Food preparation is all about science, and science is something I sadly know little about. But, fortunately for most of us, science camouflages itself in a variety of guises when it comes to cooking. Flavor, for instance. Scent. And, of course, color. Those of us who cook rely on these guises to help us along, keep us safe and please our palates. But, we really can’t forget that the chemistry behind the creation of a meal is what determines its outcome.

How else does color serve as a virtual timer? Immediately I think of recipe instructions like “Beat eggs until light”. Or “beat butter until it turns a soft yellow”. We know meat is rare because it’s got a red interior. If chicken is pink inside we know it needs more time to cook. We brown meat and vegetables. We saute onions until translucent or they start to brown. But, we don’t want butter to brown. Or garlic. If we pay attention to color while we cook, we learn all about timing. And, it makes us better cooks.

How Green is your Bean? Or, How Color Teaches Us How to CookSome of the best examples of color as an automatic timer have to do with produce. Let’s look at green vegetables, like beans or asparagus or Swiss chard.

Blanche, steam or saute greens briefly and they put on a vibrant show. It’s all that heat that causes the gases around vegetable cells to expand and escape, according to a piece I once read in Sunset magazine. It allows you to see the beans’ green pigment—the chlorophyll—in its clearest state. But, it’s only that first blast of heat that does it. Keep on cooking the green veggies or cook them covered or in just a little water and you’ll find that gorgeous, brilliant color fade and turn to a grayish olive tint. What’s happening? That unstable chlorophyll is being attacked and the cells begin to escape. The whole chemical structure has shifted. And, they aren’t going to taste very good either. If you don’t pay attention to color, you’ll have overcooked greens.

How Green is your Bean? Or, How Color Teaches Us How to CookThe heat/color relationship is especially dramatic when it comes to one of my favorite farmers market beans, Dragon Tongues.

These gorgeous swirls of purple and cream are just so sexy and appealing. But the uninitiated are bound to be disappointed when they take them home and put them in the pot. Cooking Dragon Tongues causes their color to fade away to a shadow of their sexy selves. The good news is that they are delicious raw, so make a nice yogurt- or buttermilk-based dipping sauce or slice them into a salad for the visual wow! factor.

Another strange color phenomenon that surprises home cooks is the transition red cabbage makes to blue when it’s cooked. The red needs acids like lemon juice or vinegar to maintain the color. Neglect to add it and you’ll wind up with a very weird looking blue veggie.

In fact, acid is a must for peeled and sliced potatoes, artichokes and apples that aren’t going to be cooked right away. It keeps them from turning brown when the air hits them. On the other hand, acid can destroy green vegetable color, turning them an unappetizing yellowy gray-green. More chemistry, of course, but to avoid a clash of atoms, simply wait to add dressing to vegetables until you’re about to serve them.

How Green is your Bean? Or, How Color Teaches Us How to CookFinally, there’s blackening veggies with a skin, like peppers. I adore roasted red or yellow or orange peppers marinated in olive oil, garlic, herbs, salt and pepper.

Or peppers tossed in olive oil, garlic and balsamic vinegar. They make a lovely appetizer on their own or add a magnificent dimension to a grilled sandwich filled with roasted eggplant, a fat Portobello mushroom, some fresh greens, thinly sliced red onions and provolone.

And, how do you prepare these peppers for a marinade? If you have a gas stove top, grill the peppers over the flame until the skin turns black. If not, simply put them on a sheet of foil stabilized by a flat pan and run them under the broiler, turning them periodically until they blacken. Then put the peppers in a plastic or paper bag, seal the bag and let them steam for about 15 minutes. At that point, you can easily peel that burnt skin and find racy red, but now softened peppers that you can slice into strips and layer with olive oil, garlic and other ingredients. From red to black to an even more dazzling red.

It’s all in the timing, and color can be your guide.

About our colorful guest contributor: Caron Golden has a thing for food. And farms. And markets. And restaurants. She gets to indulge in this obsession as an award-winning freelance food writer, whose work appears in Edible San Diego, San Diego Magazine, and Saveur. She is a first-class shopper and loves to share her discoveries on her blog San Diego Foodstuff.


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