The Flavor Green
by Sarah West
There is something common among the canon of spring vegetables that is found few other places—a freshness that cannot be fully preserved, a tenderness and depth of subtle flavors that quietly slips away in the heat of summer, lacks the robustness to survive winter. As spring days lengthen and the rich soils warm, the world becomes green for a few delicious months, and we dine on its delicate plenty.
Certainly leaf vegetables and herbs taste green year-round—that sometimes bitter, sometimes astringent, always tonic hallmark of healthiness—but the flavor green belongs to spring. In spring, arugula is succulent and nutty, pea shoots are soft and rich as butter, kale leaves are tender enough to eat in raw mouthfuls, lettuce’s bitter notes are balanced by sweetness and green substance. The flavor green even goes so far as to permeate the milk of grass-fed ruminants, lacing it with powerful odors (too strong for some) that taper into sweeter, floral aromas, casting the milk in deep orange hues.
The green color of plants comes, of course, from chlorophyll, the primary pigment responsible for transforming light energy into chemical energy. This explains the increase of green pigment in spring; more sunlight means plants leap into action, capitalizing on the newly available energy. But just what makes spring vegetables—and the flavor we think of as “green”—taste so opulent this time of year is more difficult to nail down.
Though most people associate chlorophyll with green-tasting foods, it is, from a cook’s point of view, mostly color. Hidden by chlorophyll’s powerful presence are concealed pigments that complement its work. When it comes to flavor, the carotenoids (ranging in color from yellow to orangey-red) may be some of the most significant of these accessory pigments. Acting as a buffer, carotenoids provide chlorophyll with light reserves as well as shield it from excess light that would otherwise cause harm.
Beyond their role as pigment, carotenoids double as precursors to flavor compounds as well as A-vitamins. Left in their whole state, functioning as light harvesters, carotenoids have neither intrinsic flavor nor odor. When processed by enzymes or oxidization, their chemical components convert to vitamins and antioxidants (as in the human digestive tract) as well as flavor.
As we chew a green leaf, the tearing action of our teeth releases enzymes present within the leaf itself that quickly convert carotenoids into some of those grassy flavors we associate with chlorophyll’s green color. Other flavor compounds are released by chewing, and in complex concert create the particular flavors we know as lettuce, asparagus, pea, and so on. Even black tea, whose chlorophyll has been converted away from green by oxidization, has carotenoids to thank for some of the lighter, grassier elements of its flavor profile.
Spring milk, too, gets its hint of green from carotenoids. Ruminants are capable of transferring the A-vitamins they’ve gleaned from carotenoids (and all associated flavor compounds) into their milk, so a diet higher in fresh forage will translate to stronger flavors (and more vitamins) than milk from primarily grain-fed ruminants. Not surprisingly, the color of spring milk, a rich yellow-orange, comes from carotenoids as well.
To me, the flavor green is equally a texture, that soft, melt-in-your-mouth tenderness only spring vegetables have. The serendipity of fresh molecular content, soft fibers, ample moisture and fewer bitter compounds may all have a hand in fashioning the subtleties of early-season flavor.
In our region, spring is a cavalcade of moisture and sunlight, one following the other in sometimes hourly successions, tempered by cool nights. While the nutritional content of spring vegetables is certainly not greater than their summer counterparts, it is available in abundant and succulent mouthfuls.