Food 101: Handle acid- and heat-sensitive green beans with care

My last semester of college-level inorganic chemistry ended with a bang. I blew up the lab.

It was an accident, of course, not a political statement. My professor had allowed me to make up an experiment while another class was in session. Unfortunately — and even though his warning to me before starting the lecture was, "Just don't do anything distracting" — a rather large flask of hydrochloric acid slipped from my hands and, to my horror, plunged to the floor.

The explosion and gagging cloud of fumes was immense. Quicker than you could say, "Look out; there's a home ec major in the chem lab!" the class emptied.

After graduation, I approached cooking with the same sense of untamed enthusiasm. My experiments were creative, if not sometimes quite disastrous.

One bad run occurred with a basketful of beautiful, fresh green beans. Forgetting my Food 101 lessons, I simmered those emerald beauties in a zesty sauce of white wine, broth and lemon juice for a good 30 minutes. They came out a ghastly shade of olive drab. Only then did I recall that I hadn't been respectful of a basic biochemical fact: Acidic substances such as lemon juice and wine have the same impact on green beans as hydrochloric acid does on lab floors.

The semester after the hydrochloric-acid episode, I moved on to organic chemistry. On the first day of class, my previous professor spotted me from the hall and stopped in his tracks. With a voice dripping in sarcasm, he asked, "You mean, you've advanced to organic?"

I nodded.

"God help us all."

At least the victims of my green-bean efforts were kinder. They actually came back for seconds.

In truth, those beans were very tasty. But they wouldn't have won me any Food Network awards for style. If you want beans to be as beautiful as they taste, there are a few things to consider.


For one thing, start with high-quality beans that are freshly harvested and refrigerated promptly. Right now, you'll be finding plenty of local beans of extremely grand quality. But give them a careful going-over anyway. The pod should be unblemished, relatively crisp, with small seeds. Fresh beans will have a slightly fuzzy skin.

Whatever variety of bean you encounter, the cooking principles are the same. Chlorophyll, the pigment that puts the green in green beans, is heat- and acid-sensitive. Too much of either, and you'll end up with a bowl of olive-drab beans.

Chlorophyll also is sensitive to the acids within the vegetable cells. It's only after the cell membranes are altered by cooking that these acids are released and able to attack the pigment. If the cooking pot is covered, then volatile acids condense on the underside of the lid and fall back into the pot. This results in ugly beans. So don't cover your beans during cooking.

I prefer cooking green beans in two stages. Stage one is to drop the beans into a large pot of boiling water. As soon as the water returns to a boil, simmer for 3 to 5 minutes just until the beans are barely tender (they'll still have a hint of crunch).

Alternatively, I steam them in a large pot, with a lid partially covering the pot, just until barely tender. Steaming retains even better flavor, but it's easier for the uninitiated to overcook beans by this method and, thus, ruin the beautiful color.

Once the beans are cooked to crunchy tenderness, whisk the pot of beans over to the sink, strain through a colander, then — unless the beans are heading straight to the table — plunge them into cold water to stop the cooking process and set the color.

At this point the beans can be refrigerated for several hours or overnight if necessary, and stage two (whatever procedure called for in your recipe, such as braising or sauteing) applied just before serving.


Cookbooks will tell you that French cutting — the act of cutting green beans lengthwise into thin strips — is recommended for mature, less tender beans. But why reserve such an exquisite preparation for only the tough, old beans? French-cut green beans more readily absorb seasonings and sauces, which means you don't have to overseason to get a balance of flavors. Hence, I almost always French cut my beans prior to cooking. Two of my recipes above reflect that philosophy.

If you only have a pound or two of green beans to deal with, then a hand-held bean slicer will do the trick. There are numerous brands on the market, but my favorite one is the Krisk Bean Stringer & Slicer. It's a fancy instrument designed with a spring-hinged tunnel that conforms to each bean's diameter and a sharp blade that whisks away the string as the bean is pushed through the slicing mechanism. This dandy little tool is typically sold in kitchenware stores.

For "company batches" of French-cut beans, I pull out my little hand-cranked French bean slicer. It's a slick kitchen tool that attaches to a counter top. To operate it, you feed a handful of fresh green beans into the hopper while turning the crank. Beans are transformed into slender, French-cut slices in short order.

I found mine at a local kitchenware store, but you may not have such luck. These machines also are available via the Internet. My brand is made by NorPro and costs around $20. If you'd like to take a look at one, go to and type in "bean Frencher" in the search box.

Jan Roberts-Dominguez is a Corvallis food writer, cookbook author and artist. Readers can contact her by e-mail at or obtain additional recipes and food tips on her blog at

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