Walnuts

Although we call and consume them as nuts, walnuts are not botanically a nut. Instead, they are the rounded, single-seeded stone fruits of the walnut tree. The tree has two major species that are grown for their seeds: Persian or English walnut and the black walnut. The English walnut is native to Persia, which is now known as Iran. The black walnut, on the other hand, is native to eastern North America.

Nevertheless, walnuts are commonly used as a garnish or a snack. Their skin has a slightly bitter flavor, but the nut meat itself is mild, earthy, and a little tangy. Before, they’re considered as a cold season food because their harvest season falls between fall and winter. But now, since there’s a sufficient supply of walnuts in California, they are available year round. Thus, they can be enjoyed even during the hot summer months, especially in Texas where they’re often topped on smoothies, ice creams, salads, and other cold specialties.

Classification Information:
Kingdom: Plantae
Order: Fagales
Family: Juglandaceae
Genus: Juglans L.
Species: Juglans Regia
Binomial Name: Juglans Regia L.

Walnut Trivia

• Walnuts have been the oldest food tree known to man. The tree dates back to 7000 B.C.
• In ancient Persia, walnuts were reserved for royalty.
• Between Asia and the Middle East, walnuts were traded along the Silk Road route. Caravans carry walnuts to remote lands and eventually through sea trade, spreading the popularity of the walnut around the world.
• When the English merchant marines transported walnuts for worldwide port trade, the nuts became known as “English Walnuts.” However, walnuts were never grown commercially in England.
• Walnuts can be eaten directly from the tree. However, the flavor is a lot milder and the texture is softer than walnuts that have been dried.

Walnut Buying Guide

Walnuts are widely available in the market. From supermarkets, convenience stores, farmers markets, up to the growers, it’s easy to find them. They’re usually harvested in between late August and November; but, since we have a good supply and outstanding modern storage techniques, especially in California, they can be purchased all-year-round. However, there can come in a variety of ways that it can be quite overwhelming to select the best ones. Thus, here are some tips that might be helpful:

• Walnuts can be purchased shelled or unshelled, either raw, roasted, salted, seasoned, or unsalted. 
• In-shell walnuts are usually available in bags or bulk bins, and they’re typically in the produce section. They’re great for holiday decorations, snacking, or social after-meal cracking sessions. However, shopping in bulk bins is not the best way to buy walnuts in the shell. It’s impossible to tell how often these nuts are being replaced, or how long were they sitting out in the open air. Knowing that air or oxygen is the number one enemy of nuts when it comes to their shelf life, we’re most likely dealing with a compromised freshness, quality, and shelf life when we buy these kinds. Furthermore, some people just stick their bare hands directly into the bins to sneak a snack. Worse, they stick their hands once again to grab another handful after they’ve just touched their mouths. Thus, those that are sealed in the bag indicates freshness as the oxygen is restricted from slipping through the package. 
• Shelled walnuts are also available in bags and bins. You can also find them in the produce section, as well as in the snacking and baking aisles of the supermarket. They’re sold in halves, halves and pieces, pieces and chopped, and other forms. As mentioned above, the ones in bags are safer to consume.
• If you hate removing the shell from the nutmeat, then shelled walnuts are your best option. However, not only that you’d have to pay double the price, but you’re more likely to eat more, as studies have shown that the process of removing walnuts and setting them beside you while eating slows down your consumption.
• Regardless if you’re buying shelled or unshelled walnuts, don’t pay too much attention to their expiration dates. These dates are just suggestions about freshness rather than strict deadlines that indicates when the nuts are no longer edible. Remember, there are three key factors that affect the shelf life of nuts: their shell, packaging, and storage conditions. Thus, a good rule of thumb is to think of them as produce rather than a packaged good. Just as you would with a bag of fresh tomatoes or lettuce, give them a good smell before you eat one. As walnuts mature, their rancidity will give them a paint smell. When you get any bitter or harsh aromas, discard them.

Walnut Production & Farming in Texas

There are 21 species of walnuts that grow from southeast Europe to the east of Japan, and from southeast Canada to west of California and south of Argentina. However, the walnut varieties in California do not yield well in Texas because of the bacterial disease called the “walnut blight.” With this disease, the trees will look vigorous and strong. But, their flowers will either fail to set fruit or the fruit will fail to ripen properly. In spring, rain and wind spread the pathogen and severe damage can occur at this time. The catkins can be infected and the pollens can be easily contaminated, spreading the blight infection to the flowers. Thus, a pesticide called Kocide 101 is usually sprayed at a rate of 2 pounds per 100 gallons of water to avoid walnut blight. Excessive use of copper sprays like Kocide 101 or the old Bordeaux mix can damage the trees. Hence, when doing so, always follow the label instructions. 

The good news is, several promising cultivars were collected and evaluated at Texas A&M University in the city of Uvalde. These cultivars are said to be resistant to walnut blight: Reda, Geoagiu 86, Orastie, Germisara, and Geoagiu 3 X 4 X 453. Under Texas conditions, these cultivars appear to be superior to the standard commercial varieties Payne, Eureka, Hartley, and Broadview.

On the other hand, the Texas Black Walnut (Juglans microcarpa) is a far superior rootstock for walnuts, growing in higher pH soils of Texas than its Eastern and Californian counterparts. The Texas black walnut grows wild in places that have full sun and deep, well-drained soil. They’re usually found in the river bottoms and the hillsides facing east or north. Given the time and favorable conditions, these trees can grow an average of 50 to 75 feet, with 150 feet being the maximum. These nuts ripen between October and November. 

Pesticides, Additives, and Chemicals:

As mentioned, Kocide 101 or the old Bordeaux mix are commonly sprayed on the Walnut trees to resist the walnut blight disease. But, besides this, aflatoxin can also be found in poorly harvested or processed walnuts – just like the other tree nuts out there. Aflatoxins are potent carcinogenic chemicals that are produced by molds, which occurs from pests, poor storage, or the soil. The contamination prevails especially in warmer and humid environments. In fact, in some cases like Kenya, aflatoxins have caused outbreaks which led to several deaths. Thus, pesticides are sometimes applied to lessen the risk of this disease. Fortunately though, exposing walnuts to heat or cooking them under pressure removes 70% of this toxin. Nevertheless, other than these two concerns, store-bought walnuts only have salt and/or natural flavorings.

Geography:

As of 2017, China is the world’s leading producer of walnuts in the shell, accounting for 51% of the global production. It’s then followed by the United States, with the state of California accounting for 99%, along with Iran and Turkey.

Packaging:

Walnut meats are available in two forms; in their shells or de-shelled. The meats may be whole, halved, or in smaller portions due to processing.

Enjoying Walnuts

All walnuts can be eaten on their own, either as raw, roasted, candied, or pickled. Raw and roasted walnuts are commonly mixed with breakfast dishes like oatmeals or muesli, but they can also be added to savory and sweet dishes like soups, pies, cakes, brownies, fudge, and more. Pickled walnuts can also be sweet or savory; this depends largely on the brine or preserving solution. Walnut butters can also be done at home and can be used as a spread on bread. Immature, green walnuts can also be steeped in alcohol and sweetened with syrup to create the Nocino liqueur. Walnut oil is also used in salad dressings and stir-fries. In Iranian cuisine, walnuts are an essential ingredient in making baklava, Circassian chicken, and meatball stew.

Storage:

One of the most important things to remember about storing walnuts and products in bulk containers is that they have been known to start fires. Nuts are generally high in fat and low in water contents, especially when their protective shells have been removed. On top of that, these kernels are more prone to self-heating and spontaneous combustion when stored with oil-soaked fiber or fibrous materials.

In addition, poor storage can also lead to insect and fungal mold infestation. Molds can lead to the production of aflatoxin, a potent carcinogen. Thus, walnuts that are infested by such should be entirely discarded.

If you are planning to consume all your walnuts in a few days, you can simply keep them in resealable bags and store them in the pantry. However, if you’re keeping it longer, place them in an airtight container and store them in the refrigerator or the freezer. Walnuts in the shell can last for up to 6 months in the fridge and 1 year in the freezer. On the other hand, shelled walnuts can be stored in the refrigerator for up to 3 months. Nevertheless, when storing walnuts in the fridge, keep them away from foods with strong odors like onions, fish, and alike as they can absorb their flavors. As walnuts mature, their rancidity will give them a paint smell. When you get any bitter or harsh aromas, discard them.

The best temperature for storing walnuts for industrial and home use is between 27 and 32ºF, along with low humidity. However, some developing countries where walnuts are produced in large quantities don’t have such refrigeration technologies. Thus, their walnuts are stored below 77ºF along with low humidity. Walnuts will last in the fridge for weeks and in the freezer for at least a month. Temperatures above 86ºF and humidities above 70% can lead to rapid spoilage. Moreover, humidities above 75% can form fungal molds that will release the hazardous aflatoxin.

Cooking:

As mentioned, exposing nuts to heat removes 70% of the hazardous aflatoxin. While this alone is a valid reason for you to cook your nuts, there’re plenty of other motives for you to do so. Roasting or toasting walnuts brings out a magnificent flavor, wonderful color, and intensified aroma. Otherwise, they’ll just look, smell, and taste dull. On top of that, the texture will also improve through cooking. They’ll stay crisp, which makes them perfect to top on salads or baked goods. And the best part is, you won’t have to buy a premium, artisanal, or gourmet nuts for this to work. All walnuts can be quickly transformed or amplified. Yet, if you buy them roasted, it has a doubled or tripled price tag? Come on!

To roast walnuts, simply spread them in a single layer on a baking sheet. Place them in the oven that’s preheated at 350ºF and roast for 10 to 12 minutes, tossing the nuts halfway to ensure even cooking. You can tell the walnuts are done when they look a shade darker and smell toasty. Cool them down and use right away, or store them accordingly. When you do the latter, make sure you consume all of them in a week or two.

Nutrition:

Walnuts are made with 65% fat, 15% protein, 14% carbohydrates, and 4% water.

Unlike most nuts that are high in monounsaturated fats, the fat content of walnuts is largely made up of polyunsaturated fatty acids, which are mainly alpha-linolenic and linoleic acid. It’s also an excellent source of protein, fiber, and manganese, along with several dietary minerals and B vitamins. 

Moreover, the USDA states that eating just an ounce and a half of walnuts a day may reduce the risk of heart disease. On top of that, it can also lower the blood pressure of those people who don’t have diabetes. They also help to keep our mind sharp; they’re waistline-friendly; they promote bone health; and they reduce inflammation too! All the more reason that they’re healthy and incredibly delicious!

When Are Walnuts in Season in Texas?