How to Cook Asparagus | Yankee Kitchen
A: Acid changes the bright green chlorophyll to yellow-green and gray-green (think of what happens when you put vinaigrette on those bright green beans). The natural acid in vegetables is liberated by heat, and when cell walls break down, color-destroying enzymes are also turned loose. Boiling green vegetables in a small amount of water means bathing them in a virtual soup of color destroyers. Add something alkaline, such as baking soda, and the chemical reactions are altered so the chlorophyll turns bright green.
Unfortunately, alkalinity also speeds up the breakdown of plant tissues. Cell walls break down, vitamins leak out — it’s not a pretty picture. The most common solution is to drop the cut up asparagus (or broccoli, or green beans, or cabbage, if it comes to that) into a big, uncovered pot full of boiling salted water. Cook only until tender, about 5 to 8 minutes, then drain promptly. Serve at once, or if you’re making salad, plunge into ice water to stop the cooking, then drain again.
This treatment works because the big vat of boiling water dilutes the plant’s acids and rapidly destroys most of the color-damaging enzymes. On the other hand, all that water does remove a little flavor and a lot of vitamins.
The solution to the solution for how to cook asparagus? Stir-fry. Stir-frying isn’t picture-perfect, but because the cooking is speedy, and the enzyme-loaded steam dissipates rapidly, it does produce tasty, reasonably good-looking results. Cut the asparagus into 1-inch pieces, on the diagonal, so the inside is exposed, and it will cook quickly. Stir-fry over high heat until just tender, 2 or 3 minutes and serve at once.