It's been a very good year for cauliflower here in this corner of the Desert Garden. Back in early Autumn, a friend and neighbor stopped by with six cauliflower plants she'd been given, and we popped them in the ground just to see what might happen.
On such happenstance are great adventures often borne.
Two of the plants are of a Romanesco type (lime green with fractal outcroppings), two are an orange cauliflower, and the last two are purple (pictured above).
One of the purple ones was the first to go, becoming lunch yesterday. After harvest it weighed in at a good pound-and-a-half, which is hefty for a cauliflower.
The purple coloration of this variety comes from the presence of anthocyanins, a water-soluble flavonoid that colors everything from sweet violets to blackberries and beech trees; the word "anthocyanin" comes from the Greek, meaning "flower-blue." In my book, the whole point of purple cauliflower is the purple; given that the purple pigment is water soluble, it seemed best to find a cooking method that would keep as much of the color as possible: soup, of course.
Cream of cauliflower soup is easy to make. As it turns out, purple cauliflower makes a cream soup that tastes much like vichyssoise, and is colored the exact shade of blueberry yogurt.
Cauliflower is a Winter-garden vegetable, as are all the cruciferous (cabbage family) vegetables. Plant it in the Fall in rich, but not over-fertilized soil, and be certain to water in the winter dry spells. I have found that a generous amount of good compost, dug into the soil before planting, makes subsequent fertilizer unnecessary. The only significant pests are cabbage looper caterpillars, which occur in small numbers, so are easy to pick off. Harvest cauliflower when the heads are well-sized, and just before the individual florets begin to separate; cauliflower quickly becomes coarse once it passes its peak.
The variety pictured above is called "Graffiti" and retains its color when cooked. There is another variety called "Violet Queen" which is also bright purple, but fades to light green after cooking. Either is good on the crudite platter, but if you have your heart set on purple soup, go for the Graffiti. Anthocyanins are pH-sensitive, so while I didn't try this myself, I suspect that adding a couple of tablespoons of lemon juice to your soup stock would preserve more of the purple color.