Kale is a close relative of collards, and grows well in colder temperatures because it can withstand frost — which helps it produce sweeter leaves. It is generally available year-round but is most flavorful and abundant in the early summer (before it gets too hot), late fall and early winter. One may differentiate between kale varieties according to the low, intermediate, or high length of the stem, along with the variety of leaf types. The leaf colors can range from light to dark, yellow-green through vibrant green to blue-green, or from violet-green to violet-brown. There are curly-leaf, bumpy-leaf, plain-leaf, and feathery-leaf kales that you’ll come across at the store or market and they all have slightly different flavors and textures.
Raw kale provides a large amount of vitamin K and is a rich source of vitamin A, vitamin C, vitamin B6, folate, and manganese. Kale is also a good source of thiamin, riboflavin, pantothenic acid, vitamin E and several dietary minerals, including iron, calcium, potassium, and phosphorus. Boiling kale diminishes most of these nutrients, while values for vitamins A, C, and K, and manganese remain substantial.
Buying & Storing
Look for bunches of kale with a nice vibrant color and not too many yellow spots. Damage to the leaves can be easily removed. Wilting kale leaves have either been in the sun for a while or are old. Wrap kale in a damp towel or in a plastic bag and refrigerate, preferably in a crisper drawer, for up to 1 week. Leaves will wilt if allowed to dry out so replace the damp paper towel as needed. For long-term storage, kale can be frozen. Wash, de-stem, and drop the leaves in boiling water for 2-3 minutes. Remove from the water and rinse under cold water or put in an ice bath to stop cooking. Drain the kale and pack into airtight containers or freezer bags.
Preparation – wash kale leaves well, checking the underside of each leaf for soil and garden pests. You can dunk them in a sink filled with cold water several times, using your hands to swish them around and push them under the water. Refill the sink and repeat as necessary. Remove stems (midrib) from mature kale leaves by folding the leaf in half lengthwise and stripping/ripping or slicing away the thick center spine of each leaf. Baby or very tender young leaves may be eaten or cooked with the stem attached, just like with spinach.
Raw: use raw kale (baby or otherwise) for salads, slice it into ribbons and add it to slaws, or season it and use it as a taco topping. Chop or slice raw kale and add it to hearty soups and stews towards the end of cooking time.
Steam – remove the stems and place kale leaves in a pot with a steamer basket above an inch or so of boiling water. Steam mature kale leaves for approximately 4-5 minutes, depending on age, size, and amount in the steamer. The kale is cooked when it is vibrant green in color, and limp, while still retaining some texture.
Sauté – remove the stems, cut the leaves into thick ribbons, and sauté in a skillet or sauté pan with butter, garlic, and onions until the kale has just started to go limp. Remove it from the heat immediately so that it doesn’t overcook.