Spinach

Botanically, spinach is part of the Chenopodiaceae family. It grows well in temperate climates in both the spring and autumn (avoiding the hot part of the summer). Today, the United States and the Netherlands are among the largest commercial producers of spinach.

There are three main types of spinach generally available. Schreiber & Sons grows all three, so any one may be found in your box.
Flat or Smooth Leaf: Flat or smooth leaf spinach has unwrinkled, spade-shaped leaves that have a milder taste than the savoy. This variety is commonly used for canned and frozen spinach as well as for soups, baby foods, and other processed foods. Flat leaf spinach is usually the preferred choice for raw dishes, as it has a much milder flavor.
Savoy:Savoy has crinkly, dark green curly leaves. The texture is different from the flat leaf but tastes equally as good.
Semi-Savoy:Increasing in popularity is the semi-savoy variety, which has slightly curly leaves, is less-pungent and much easier to clean. This variety is usually sold fresh. It is also found in processed foods.
Spinach is thought to have originated in ancient Persia (Iran). It made its way to China in the 7th century when the king of Nepal sent it as a gift to this country. Spinach has a much more recent history in Europe than many other vegetables. It was only brought to that continent in the 11th century, when the Moors introduced it into Spain. In fact, for a while, spinach was known as "the Spanish vegetable" in England.
Spinach was the favorite vegetable of Catherine de Medici in the 16th century. When she left her home of Florence, Italy, to marry the king of France, she brought along her own cooks, who could prepare spinach the ways that she especially liked. Since this time, dishes prepared on a bed of spinach are referred to as "a la Florentine."
In the history of food, spinach has the claim to fame of being the first frozen vegetable sold.
Storage and Use: Fresh spinach should be dried (or not washed at all) and packed loosely in a cellophane or plastic bag and stored in the refrigerator crisper. If stored properly, it should last 3 or 4 days. Avoid storing cooked spinach as it will not keep very well.
Preparation: We have washed the spinach you receive, however, it grows in sandy soil, so wash it thoroughly again to get rid of the grainy, sandy particles. Tear off the stem (though it is edible as well). Separate the leaves, and place them in a large bowl of water, rinse several times.
Although 19th century cookbooks called for boiling spinach for 25 minutes, the green can be eaten raw, or for even more nutritional benefit, cooked for as briefly as 1 minute. Spinach cooks down to about one-third its uncooked size, so pile your pan full of raw leaves. As mentioned below, cooked spinach provides three times the nutrients of eating it raw (I believe this is equal to the amount of reduction during cooking), so you are better off nutritionally to eat the vegetable cooked. For extensive cooking instructions, see the end of this publication.
Raw: If spinach is to be eaten raw, dry it completely by using a salad spinner or by blotting it with paper towels.
Blanching: Drop leaves into a large pot of boiling water. Once the leaves slightly wilt, drain and squeeze out excess moisture. This method is used to quick-cook spinach or to prepare it for sautéing, braising, or stuffing, and usually takes 2 to 5 minutes.
Microwaving: This method can be used instead of blanching. Place washed, slightly wet spinach in a microwavable dish, loosely cover, and cook until tender (4 to 7 minutes for ½ pound of spinach).
Sautéing: Blanched spinach can be sautéed quickly with a quick spray of oil. If cooked in a non-stick pan, only a spray is needed for several cups of chopped spinach. Try adding some garlic for flavor.
Steaming: If you plan to steam the spinach, do not dry leaves after washing. Steamed spinach makes a great side dish and usually takes only 5 to 10 minutes.
Nutritional Benefits
Popeye made himself super strong by eating spinach, but he may not have known he was also protecting himself against osteoporosis, heart disease, colon cancer, arthritis, and other diseases at the same time. Calorie for calorie, leafy green vegetables like spinach provide more nutrients than any other food. It is rich in a number of essential nutrients, including calcium, folate, iron, magnesium, vitamin C and vitamin A. Spinach is also a great source of lutein and zeaxanthin, two carotenoid phytonutrients that are important for healthy eyes.
Eating about one cup of raw spinach offers roughly one-third of the nutrition as half a cup of cooked spinach (which is actually equal to about three cups raw). So, while spinach makes a great addition to cold salads and sandwiches, enjoying your spinach hot packs a better nutritional punch.
Important note: Although spinach is in fact a good source of both calcium and iron, it’s important to note that certain compounds found within spinach, called oxalic acids, block the absorption of these two minerals. Iron and calcium in plant foods are not highly absorbed by the body. Spinach contains a chemical called oxalic acid, which binds with iron and calcium and reduces the absorption of these minerals. To improve iron absorption, spinach should be eaten with vitamin C-rich foods such as orange juice, tomatoes, or citrus fruit.
Researchers have identified at least 13 different flavonoid compounds in spinach that function as antioxidants and as anti-cancer agents.
The vitamin K provided by one cup of fresh spinach leaves is almost 200% of the Daily Value and in one cup of boiled spinach, over 1000% of the Daily Value. Vitamin K is important for maintaining bone health. Spinach is also an excellent source of other bone-building nutrients including calcium and magnesium.
Spinach is also an excellent source of folate (65.6% of the daily value in one cup boiled) and an magnesium (full daily value).
The vitamin C and beta-carotene in spinach help to protect the colon cells from the damaging effects of free radicals. And the folate in spinach helps to prevent DNA damage and mutations in colon cells, even when they are exposed to cancer-causing chemicals.

In animal studies, researchers have found that spinach may help protect the brain from oxidative stress and may reduce the effects of age-related related declines in brain function. Researchers found that feeding aging laboratory animals spinach-rich diets significantly improved both their learning capacity and motor skills.

"On the subject of spinach: divide into little piles. Rearrange again into new piles. After five of six maneuvers, sit back and say you are full."
Delia Ephron, How To Eat Like A Child