Walnut at a Glance
| History | Uses | Name Origin | Folklore/Oddities | Medical Benefits |
|---|---|---|---|---|
| Growing | Nutrition | Purchasing | Preparation | Recipe |
One day Jim climbed into his truck, revved up the engine a bit, and drove back and forth in his driveway about half-dozen times before getting out of the vehicle. His neighbor, Bill, was watching this process quizzically and thinking that Jim was behaving oddly.
"Watcha up to, Jim," Bill asked.
"Oh, not much," Jim answered, "Just crackin' a few black walnuts--that's what it takes, ya know,"
Imagine a nut so tough to crack that it takes the weight of a car to loosen the hull. While the familiar Persian walnuts, often called English walnuts, can be cracked easily, often by holding two of them in the palm of the hand and squeezing, the black walnut and the butternut require the utmost of "S" and "S"--strength and strategy. These natives of North America sport the toughest husks that cling firmly to their tough shells.
One garden reference actually does suggest driving a car back and forth over the whole nuts to loosen their husks but warns that this method could permanently stain the driveway. The husks are frequently used as a dye. One nut lover recommends smashing the hulls with a determined swing of the hammer on a hard surface, while another suggests stomping on them with the heel of the foot.
Because of their hard shells, walnuts were well protected from light, heat, moisture, and water and could last for months before spoiling, making them the ideal world travelers--the perfect food for a long journey across many oceans to become everyday food throughout the globe.
History
The oldest archeological site where walnuts were unearthed is in the Shanidar caves in northern Iraq. Following that find, at a considerable distance from Persia, evidence of walnuts was discovered in a Mesolithic dunghill in Switzerland.
During the New Stone Age or Neolithic period, items found in Switzerland's lake district included walnuts. The Neolithic period began in Southwest Asia from about 8,000 BCE and expanded throughout Europe between 6,000 to 2,000 BCE.
You may have heard walnuts referred to as Persian walnuts. In ancient Persia, only royalty was privy to the pleasure of devouring the walnut, the fruit referred to as the Royal Walnut.
Mesopotamia, the area that is now modern Iraq, boasted of walnut groves in the famed Hanging Gardens of Babylon about 2,000 BCE. As testimony, Chaldeans left clay tablet inscriptions that accounted for these orchards. These were the earliest written records mentioning walnuts.
Slightly later, about 1795 BCE, Hammurabi, the 6th king of the 1st dynasty of Babylon, set down a code of laws known as the Code of Hammurabi. These laws were incribed on black diorite pillars and categorized by subject. Mention of walnuts was included in the section on laws governing food.
In the Song of Solomon 6:11 of the Old Testament, King Solomon is quoted, "I went down into the garden of nuts to see the fruit of the valley." These words refer to walnut groves flourishing and producing abundantly.
The first cultivation of walnuts is attributed to the ancient Greeks, but it may have actually been the Persians who first cultivated a superior variety. The walnuts growing in Greece were small and didn't produce a significant quantity of oil. When the Greeks encountered the larger Persian walnuts, they began to improve their variety by cultivation. The ancient Greeks utilized the walnut not only for food, but also as a medicine and a dye for the hair, wool, and cloth.
About one hundred years after the Greeks were commonly using walnuts, the Romans discovered their merits and were willing to pay dearly for the luxury of serving them along with fruits for dessert. In the ruins of Pompeii whole, unshelled walnuts were among the foods on the table at the Temple of Isis on that fateful day of August 24, CE 79 when Mount Vesuvius erupted.
Though written records of the walnut's arrival in Kashmir are absent, walnuts were an established presence and, from there, may have journeyed to China during the Han dynasty, some time between 206 BCE and 220 CE.
Since trading existed long before written records, merchants, explorers, and conquerors were credited with bringing the walnut from the Mediterranean into Europe, possibly during the third century BCE. Some historians question this theory because of archeological evidence discovered in Switzerland centuries earlier.
It is possible that during the last Glacial Period, known as the Pleistocene era, walnut trees disappeared from the frozen earth of the Northern European countries. After that era, barbarian invaders and Greek and Roman conquerors brought the trees from their homelands into Europe.
In spite of the frequency with which walnuts are referred to as English walnuts, they didn't really penetrate the English soul until after World War I when they became a commercial enterprise. Though the English climate didn't provide the most ideal conditions for growing walnuts, some trees survived nonetheless.
The first mention of the walnut's arrival in the British Isles appeared in the Encyclopaedia Britannica dated 1567. However, walnuts were only acceptable served at the end of a meal along with port and Stilton cheese.
In contrast, the French went nuts over the walnut. Early cultivation began there during the fourth century. Charlemagne, eighth to ninth century, ordered his gardeners to plant walnut trees on his extensive properties. Walnuts were so highly regarded that during the eleventh century, the French peasants were expected to tithe walnuts to the church.
From Medieval times up until the end of the 18th century, Europeans were blanching, crushing, and soaking walnuts and almonds to create a rich, nutritious milk, a common household staple. While the poor dined on the wild walnuts, the rich were able to afford the larger, more expensive, cultivated variety.
Toward the end of the 17th century, walnuts along with chestnuts became important staples in France. During the famine of 1663 the poor consumed their walnuts and then resorted to grinding up the shells along with acorns to create coarse, unpalatable bread.
In World War II when families living in the small villages of Perigord, a region in the southern part of France, had little to eat, they turned to their walnut groves for a source of protein.
The Black Walnut, a Native of North America
Wherever the black walnut grows, there is limestone in the soil, a good sign of fertile soil. The early Pennsylvania Dutch made a point of selecting properties that had a stand of sturdy black walnut trees on the land, assuring them of rich soil.
The early colonists carried seeds of the English walnut to the New World and planted them diligently where they settled in Massachusetts and Virginia. However, the trees did not adapt to their new climate and didn't even survive long enough to bear fruit. Black walnuts, however, were plentiful and soon became a valued ingredient in cookies and confections.
Walnuts Enjoy California Sunshine
During the first half of the 1800's, land grants of several acres were issued, and ranchos were established. Walnut groves became well established on these land grants by the1870's in Southern California near Santa Barbara.
In 1867 Joseph Sexton, a horticulturist, initiated California's first commercial walnut enterprise when he planted a grove of English walnuts in Goleta, a small town in Santa Barbara County. Within a few years, 65% of all fertile land in this region was planted with Sexton's English walnuts.
In spite of this early success, by the late 1930's the commercial walnut business was destined to move northward to Stockton, California, where improved irrigation, better pest control, ideal climate, and rich soil were more conducive to larger yields.
Today, the California walnut has found its ideal home in the center of the state, an area that produces 99% of the commercial United States walnut supply. On the global market, California produces two-thirds of the world's supply of walnuts. Other countries that grow commercial walnuts include Turkey, China, Russia, Greece, Italy and France.
Though the first walnuts to arrive in the United States came from Spain in the early 1800's, the French contributed many of their varieties during the latter part of the nineteenth century.
Walnuts Featured in World Cuisines
Baklava, a well-known delicacy served throughout the Middle East, is a rich dessert made of alternate layers of buttered filo dough and ground walnuts. A final topping of sweet spiced syrup is poured over the top and allowed to soak in for several hours before the baklava is cut into diamond shapes and served.
Though we are most familiar with fully mature walnuts, green walnuts, completely edible but quite sour, are an ideal ingredient for pickles, jams, and marmalades. During the seventeenth and eighteenth centuries, many English cookbooks touted an abundance of recipes for pickling both black and green walnuts.
In the Middle East, a sweet syrup is used to preserve half-ripe walnuts, a process that takes several weeks before the delicious confections are ready to eat.
In Italy, walnuts are sometimes added to the pine nuts in the preparation of pesto, a thick basil and olive oil sauce served over pasta. The French enjoy their Walnut Soup and relish sauces made of walnuts, garlic and oil, while the Persians favor a dish called Fesenjen made of poultry or meat, walnuts, and pomegranate juice.
The ancient Persians made a paste of ground walnuts and used it to thicken soups and stews. During the Middle Ages this handy technique was introduced into Europe. Before the colonists arrived in America, the Narragansett Indians of the Eastern United States also pounded the black walnut into a paste to thicken their soups and vegetable stews.
During the fourteenth century, walnuts appeared on the dessert list at a French royal banquet. The walnuts for this occasion were preserved in a spiced honey mixture that was stirred once a week for several weeks in preparation for the event.
Naming the Walnut
Another Roman version, Jovis glans, though not its botanical name, is translated as the royal nut of Jove, another name for Jupiter who is the highest god in Roman mythology.
Yet another Roman name for the walnut, Nux juglandes, translates as "the nut of Jupiter."
Because the walnut shell has an appearance reminiscent of the human brain, the Afghanistani word for walnut is charmarghz or "four brains" in their language.
From Teutonic roots comes the German Wallnuss or Welsche Nuss. Since many words of our English language came from the German, it's quite apparent how the word wallnuss could have easily evolved into "walnut."
Folklore
There is a legend that presumes walnuts were one of the gifts presented to Jesus by the three wise men.
English merchant sailors transported walnuts across the globe during Medieval times. Walnuts became so associated with the English that they were often called English walnuts, a name that is still used today.
One custom in Poitou, France is to have the bride and groom dance around the city's gigantic walnut tree. The villagers believe that by participating in this dance the bride will produce an abundance of milk for her baby.
In the French countryside, it was tradition to hang a bag of walnuts from the ceiling beam in the kitchen to represent abundance. Walnuts also represented longevity.
Some young men in the French countryside believed the walnut tree to possess aphrodisiac powers and attempted to sneak a leaf into the shoe of a young woman they admired.
Along with some items of amusing folklore, the walnut tree holds a few dark superstitions. In seventeenth century Italy there was a walnut tree, the Tree of Benevento, that was believed to be the place where witches gathered. According to a legend, the Bishop removed the tree, roots and all, but another witch-haunted tree grew where the original stood.
Another legend warns it is unlucky to plant walnut trees too close to a stable because it might bring illness and death to the animals. Even travelers along the road were warned not to choose the walnut tree as a refuge for the night, fearing they may become ill.
Superstitions and fears also surrounded the shade of the walnut tree. A passage in Pliny's writings states that the shadow of the walnut tree dulled the brain. He also considered the walnut tree a nuisance wherever it was planted.
Another superstition warns that one should not try to grow anything near the walnut tree, because it contains evil or poison.
The medieval Doctrine of Signatures stated that because the shape of the walnut resembled the brain, the nut would be beneficial for all ailments associated with the head and brain, including headaches. Later, toward the end of the fourteenth century, walnuts were thought to cause headaches.
One superstition held that if a walnut were dropped into the lap of a person suspected of being a witch, she would be unable to rise from a sitting position as long as the walnut remained in her lap.
Growing
Juglans nigra, or the Black Walnut, grows mainly in the Eastern and Central United States, from New England to Minnesota and Nebraska, and south to the Gulf of Mexico. The black walnut can grow to a height of 150 feet, with the nuts bearing a more rounded shape. Though the tree is grown mainly for lumber, there is a minor industry in harvesting the nuts because of their distinctive, rich, and oily flavor that is valued for baking, candymaking, and preparing black walnut ice cream. The black walnut tree is known to be a centenarian, living for 100 years or longer.
The walnut consists of three distinct parts. The edible portion, known as the kernel or fruit of the nut, is actually the seed of the walnut tree. It has two lobes. The inner part of the lobe is ivory colored and is covered by a thin brown skin that is firmly attached.
The shell, called the endocarp, is a very hard material made up of two distinct halves firmly sealed together. The shell is light brown in color and has an appearance reminiscent of the convolutions of the human brain. An inedible, thin, cellulose-like membrane separates the two lobes of the walnut inside the shell.
The husk, called the pericarp, covers the shell with a soft, fleshy, green skin that protects the walnut. When fully mature the husk is about two inches in diameter. Not commonly known, is that the very immature green husk is edible. At this stage the shell and the nut have not hardened and both are also edible, though they taste quite sour.
All walnut trees are deciduous and grow well in temperate zones if sheltered from extreme cold and strong wind. They thrive best in deep, fertile soil free of alkali and should not be planted closer than 60 to 70 feet apart. The trees will grow easily on mountainsides up to an altitude of 3,000 ft.
Walnut groves must be irrigated frequently because the trees require an abundance of water to produce nut kernels that are moist and well developed. However, it is also necessary to provide good drainage. Deep watering in the winter is important.
In Europe the trees grow to a height of 60 to 85 feet with a typical trunk circumference of 3 feet. One farmer recorded a circumference of 16 feet in a farmers' almanac. In the United States walnut trees can grow to a height of 20 feet in 6 to 8 years and finally reach about 90 to 100 feet when mature.
Those superstitions about not being able to grow anything in the soil surrounding the walnut tree actually have truth and reason to back them up. The tree's roots tend to secrete juglone, a poisonous substance, into the soil that actually poisons some plants growing near the trees. Horticulturists recommend not planting tomatoes, rhododendrons and azaleas within 80 feet of any walnut tree.
Each tree produces both male and female flowers that bloom in April and May, about the same time the leaves begin to appear. Though the trees self-pollinate, most growers will plant one or two other varieties in the grove for optimum cross-pollination.
In the United States, California's Sacramento Valley is the center of walnut production, whereas in France, Perigord is known for its abundance of walnut groves that were thriving well before1657.
Throughout Europe the two varieties of walnut are the Juglans regia, the familiar commercial walnut, and the black walnut, Juglans nigra.
The English walnuts reach maturity in the early fall when the husks split open. The black walnut and the butternut also mature in the fall season.
Before the age of mechanization, the traditional September harvesting of walnuts consisted of shaking the trees by hand using long hooked poles to knock the nuts to the ground where they could be easily gathered. Today, the trees are shaken by machine, while another machine uses vacuum suction to collect the fallen nuts.
Commercial hot-air dehydrators with blower fans circulate warm air to reduce the moisture of the walnuts to between 12 and 20% to preserve their shelf life. In past centuries, walnuts were simply left on drying racks away from the sun until they were properly dried.
Medicinal Benefits
A study published in the American Journal of Clinical Nutrition, May 1994, showed that those whose diets included nuts, either walnuts or almonds, were able to lower their LDL cholesterol by 9 to 10%.
Another study that appeared in the Journal of the American Dietetic Association, July 1995, found that walnuts could also diminish the extent of heart damage after a heart attack.
From ancient times through the nineteenth century herbalists prescribed the walnut, the bark, the roots, and the leaves as an astringent, a laxative, a purgative to induce vomiting, a styptic to stop bleeding, a vermifuge to expel worms or parasites, and a hepatic to tone the liver. The walnut served to induce sweating, cure diarrhea, soothe sore gums and skin diseases, cure herpes, and relieve inflamed tonsils.
The nut itself was used to prevent weight gain, calm hysteria, eliminate morning sickness, and to strengthen one's constitution. The hulls were boiled and used to treat head and body lice, herpes, intestinal parasites and worms, skin diseases, and liver ailments. The leaf was decocted to cure boils, eczema, hives, ulcers, and sores.
Even the walnut oil was employed as a medicinal aid. It was first diluted before it was used to treat colic, dandruff, dry hair, gangrene, and open wounds, while the green rind of the walnut was used to treat ringworm.
Uses for the Walnut Tree
In past times walnut shells served many purposes as well. Pliny suggests crushing them finely to use for filling dental cavities. Imagine shaving with the edge of heated walnut shells instead of a razor. King Louis XI's barber engaged in this practice because he thought it would prevent nicks. To prevent bread from sticking, bakers would spread powdered walnut shells on the base of their ovens.
More recently, finely powdered walnut shells served many commercial industries. The powder was employed as a polish for metals used in the aeronautical industry and as face powder in the cosmetics field. Oil riggers use the powdered shells to sharpen their drills.
NASA has even put powdered walnut shells to use as thermal insulation in rocket nose cones. Apparently, the powder can withstand extreme temperatures without carbonizing.
The French have created a fine liqueur with walnut husks as its base, but leave it to the Italians to create Nocino, a renowned cordial made from green walnuts. The recipe originated in Modena, where the unripe walnuts are picked on the Festival Day of St. John on June 24. The walnuts are cracked, steeped in alcohol for two months, and then filtered to remove any debris before the cordial is sipped with gusto.
In past centuries people discovered that all parts of the walnut could be processed to create colors and dyes. Furniture makers and finishers use the husks to create a rich walnut stain. Women developed a beauty secret to enhance their appearance, a hair dye made from the walnut hulls. Scribes made a rich brown ink from walnut hulls. Since prehistoric times weavers extracted a rich dark brown dye from walnut juice, while they used the green husks to make a yellow dye. The also boiled the bark to extract a deep brown dye used for coloring wool.
Walnut Oil
In France during the eighteenth century, before walnuts were pressed into oil, they were stored for two to three months to cure. To extract walnut oil, the nuts were first crushed into a paste. The most highly valued oils were achieved by heating the paste delicately to bring out the best flavor of the nuts. Next, the nuts were pressed to extract the oil. Oil could also be extracted from walnuts without heating, but heating was preferred, resulting in exceptional flavor. It takes about four pounds (approximately 2 kilograms) of nuts to press out a scant quart (a liter) of oil.
Aside from the delicacies of the table, walnut oil served rather diverse purposes. The ancient Egyptians used the oil in the embalming of their mummies. Parts of Europe where walnuts were plentiful used a lower quality of the oil to light their oil lamps. In nineteenth century France walnut oil was used in the church as holy oil.
Nutritional Benefits
While one-fourth cup of raw, unsalted walnuts contains 180 calories, be aware they contain 18 grams of fat, 1.5 grams saturated. The fat in walnuts is mostly polyunsaturated. If you are watching the fat, you can calculate your fat intake by dividing the 77% of calories from fat by the180 calories to learn that a one-fourth cup serving contains 43% fat. That percentage may sound high, but it should not discourage a healthy person from gaining nutritional benefits from eating walnuts in small quantities.
Walnuts are rich in protein, providing 7 grams for that same one-fourth cup, 2 grams of fiber, and only 7 grams of carbohydrates. Walnuts can be considered a super food because they contain a full complement of vitamins, including B1, B2, B3, B5, B6 and folic acid. They also contain a wealth of minerals, such as iron, magnesium, potassium, and zinc.
Walnuts contain Vitamin E--alpha, beta, delta and gamma-tocopherol, making it exceptionally high in antioxidants.
Nutritionists tell us that Omega 3 fatty acids are found in only a few plant food sources, yet are essential to a healthy body. In a 2,000-calorie diet, 3 tablespoons of walnuts will provide our daily requirement of these Omega 3 fatty acids.
Using Walnut Oil
Purchasing, Storing and Preparing Walnuts
When shopping for walnuts in the shell, make sure they do not smell rancid. Shake the nut. If it rattles, the kernel is old and dried up. Look for shells that are undamaged and contain no cracks or wormholes.
Though it is a rarity to find black walnuts or butternuts for purchase in the west, they may be available along the U.S. East Coast. They are almost always sold in shelled form because the nuts are difficult to extract from the shells. Packed in plastic bags and stored in the freezer, they keep up to one year.
Though many historians pinpoint Persia as the country of the walnut's origin, confusion persists because archeological remains of walnuts were found as far eastward as the Himalayas and to the distant west and northwest of Persia into Turkey, Italy, and Switzerland as well.
Traveling slightly eastward, archeologists delicately brushed away layers of dirt in Perigord, France, from Peyrat to Terrasson, to uncover petrified roasted shells of walnuts from the Neolithic period.
Native American Indians enjoyed the pleasures and health benefits of the black walnut well before European explorers arrived. The upper Great Lakes region provides archeological evidence of walnut consumption dating back to 2000 BCE. Along with eating the walnut itself, the Indians used the sap of the walnut tree in their food preparation.
In the early 1800's Spanish Franciscan monks established missions along the California coast. Part of their teachings included the cultivation of food plants and trees in the areas surrounding the missions. One area that eventually became the city of Walnut, California, was home to the San Gabriel Mission named for the Gabrielino Indians, originally of Shoshone origin. Many acres of walnut trees, originally brought from Spain, were planted here and became known as "mission walnuts." These first walnut trees produced small nuts with very hard shells.
Creative cooks and chefs of many countries have eagerly adopted walnuts and incorporated them into a multitude of dishes from soups to desserts and even dessert cordials.
The origin of the word nut is derived from the Latin nux referring to the fruit inside the shell, the nut kernel itself. The walnut tree's formal botanical name, Juglans regia, comes from the Romans. The word juglans, from the Latin, means "the acorn of Jupiter," while regia refers to royalty. You could actually translate its Latin name to mean "the royal acorn of Jupiter."
The Romans associated the walnut with the Juno, the Roman goddess of women and marriage and the wife of Jupiter. This association led to the unique wedding practice of throwing walnuts at the bride and groom as a symbol of fertility. Women often carried walnuts to promote fertility.
Walnuts belong to a family that includes the pecan and hickory pecan. There are three main varieties of walnut trees, the most familiar variety being Juglans regia, known as the Persian or English walnut. For the past two centuries its main growing region has been North America, specifically California. Southeastern Europe also grows many varieties of the English walnut which is also cultivated from Turkey to the Himalayas and even reaching into China. This variety grows to a height of 40 to 60 feet high and has a lifespan of about 60 years or more.
Juglans cinerea, refers to the Butternut, or white walnut, that is also in the same family and grows in the Eastern United States as well. The butternut tree averages about 30 to 50 feet in height and bears an oval or egg-shaped nut. Considered the hardiest of the walnut trees, its lifespan varies from 50 to 75 years. In some varieties of the Butternut, the bruised leaves and the husks are aromatic.
In one region of southern France known as Perigord the long-standing traditional diet is very high in fried foods, rich meats, and fatty patés. Yet, the people suffer fewer heart attacks than Americans. At first medical experts explained this phenomenon by attributing this miracle to the red wine they drink. Red wine is known for its superior antioxidants to protect the heart. Yet, the residents of this region didn't drink any more red wine than those in other parts of Europe. Closer examination revealed that their daily green salads were dressed with walnut oil and chopped walnuts, helping to lower their levels of LDL and overall cholesterol in the bloodstream.
The walnut tree has provided the creative entrepreneur many opportunities. The wood of the tree is exceptionally hard, making it ideal for fine furniture, wall paneling, musical instruments, sculpting, and woodcarving. The walnut wood has found its way into the kitchen in the form of plates and spoons, while the farmer employed the wood for animal yokes and water jugs. Even wooden shoes were formed from the walnut tree. During war times the Europeans made gunstocks from the firm wood of the walnut tree. During World War I, the hardy wood of the black walnut was used for making airplane propellers.
Though the walnut oil was used for many purposes, the first pressing of the walnut kernel was highly prized by chefs for its lightness and delicate flavor. High in polyunsaturates, walnut oil is also rich in gamma-tocopherol, a form of Vitamin E considered nutritionally superior. Since it is so high in antioxidants, the gamma-tocopherol protects the oil from becoming rancid quickly.
European artists favored walnut oil as a paint medium to be mixed with pigment. In fact, many of the French impressionists preferred it to poppy and linseed oils that actually surpassed it in quality. The paintings of Monet, Pissaro, and Cezanne carry traces of walnut oil as shown by chemical analysis.
Nuts are a highly concentrated form of excellent nutrition; however, it's important to stress that they ought to be eaten in moderation. Because walnuts, like other nuts, are high in fats, it's important to note they are also high in calories.
All vegetable oils are high in calories, and all should be used sparingly. Walnut oil contains 260 calories per ounce. One tablespoon contains 120 calories and 14 grams of fat. Use small amounts as a salad dressing or drizzle delicately over steamed vegetables.
Since walnuts are harvested in early autumn, usually in September, the freshest nuts are purchased during the autumn season. The supermarket will sell walnuts by the pound in bulk throughout fall and winter. If kept in their shells, they can keep for six to eight months without spoiling. Shelled nuts are usually sold in 1 pound plastic packages and are best kept in the refrigerator to prevent rancidity. For longer storage, pack them in heavy plastic bags and store them in the freezer.
