Where would we be without lemons? They garnish our drinks and liven up our food. Delicious paired with garlic, they are an imperative with anything remotely fishy. Lemons even teach us lessons: When life gives us lemons, as the saying goes, we make lemonade. They've become so ubiquitous that it's hard to believe that they are a relatively recent addition to our kitchens.
A Brief History
Somewhere along the way, someone in India or China crossed a bitter orange (Citrus × aurantium) with a citron (Citrus medica) creating the lemon (Citrus x limon). The exact origin is still a mystery, but the lemon made its way along trade routes west to southern Italy around 2,000 years ago. While lemons were not widely cultivated by the Romans, a fresco of an orchard discovered in the ruins of Pompeii reveals a lemon tree among other exotic fruits -- a tantalizing clue of the lemon's presence in the Roman Empire.
By the Middle Ages, cultivation had spread to Persia and to countries along the Mediterranean via the Arabs. But lemons were still used mostly as a source of medicine or as brightly colored ornaments for Islamic gardens. This began to change in the 15th century, but lemons were more commonly seen in greenhouses of the aristocracy than the local greengrocer well into the 1800s. Here in the US, lemons followed Spanish influence, taking root in Florida and California. It wasn't until the rise of long distance shipping and transcontinental railroads that lemons became readily available around the country.
- The first known reference to lemons in print was in a 10th Century Arab treatise on agriculture, alchemy, astrology and magic.
- The word lemon traces back to the Arabic word laymun.
- Botanically, lemons are berries, and the lemon tree is an evergreen.
- Christopher Columbus brought lemons seeds to the New World on one of his early voyages to Hispaniola.
- The Eureka lemon is the most commonly grown cultivar in the United States, favored for its year round growing season and lack of thorns. Before the development of the Eureka in the 1870s, the Lisbon lemon was the most popular variety.
- Conventionally produced lemons are hand-picked while green, treated with fungicide and coated in wax, turning their characteristic yellow hue after a period of storage, also known as curing.
- Lemons are between 5 percent and 6 percent citric acid, which is why they are so mouth puckeringly tart.
Lemon trees, which grow anywhere from 10 to 20 feet, need warm weather, lots of water and abundant sunshine, making them perfect for subtropical and Mediterranean climates. They are generally cloned onto rootstock as many hybrids are sterile, but some lemon varieties can be grown from seed. However they need about eight years to produce fruit.
For those of us in colder climes, Meyer lemons make lovely indoor plants.
In the United States, lemons are predominantly grown commercially in California followed by Arizona and Texas. While one readily associates citrus with Florida, commercial lemon production halted 10 years ago after a series of devastating freezes and disease. The US ranks behind China, India, Mexico, Argentina and Brazil in global production.
Due to global imports and the dominance of the season-less Eureka and Lisbon varieties, the lemon is available in supermarkets all year round. The Meyer lemon, however, is typically available from December until May.
Because they need to store -- or cure -- for a period of time before shipment, lemons spend a lot of time off the tree before they reach your kitchen. Conventional lemons are treated with imazalil, a fungicide, after harvest to prevent mold and stem rot, in addition to a coating of wax -- often petroleum or shellac-based.
If that wasn't enough of a bummer, imazalil has been labeled "likely to be carcinogenic" by the Environmental Protection Agency. And while the lemon is not on the Environmental Working Group's "Dirty Dozen," a study by the Food Additives & Contaminants journal revealed that 95 percent of sampled citrus tested positive for pesticides. With that in mind, you should buy organic lemons when possible, and give them a good scrub when you can't. (*See our Real Food Rule of Thumb, below.)
But the citrus industry is under threat from a disease called citrus greening or Huanglongbing. Spread by insects, the blight is ravaging groves across the world. In an effort to beat back the disease, producers are either pulling out and burning down affected trees in order to quarantine the blight or resorting to a controversial tactic of "chemotherapy." Another tactic is genetic modification. While there are currently no GMO lemons on the market in the US, that may change as the blight forces the industry to take drastic measures in order to survive.
So perfectly yellow and sour, the now-ubiquitous lemon is practically an international symbol for both of these qualities.
What to look for
Look for lemons that are bright and evenly colored. A dull lemon is a sign that it's been sitting in your supermarket past its prime. Lemons should also be firm yet not rock hard and should feel heavy -- a sign that it has a lot of juice!
Nutrition and effects on the body
Lemon juice is a great source of Vitamin C, and a good source of both folate and potassium. The essential oil from the peel can be used as an antiseptic on wounds or as a natural alternative to toxic hand sanitizers. In ayurvedic medicine, lemons aid in proper digestion and detoxification of the liver.
Lemon juice has also been used for ages as a natural alternative to hair bleach, as well as a deodorant.
What to Do with It
Lemons should be considered a staple of any kitchen like salt and spices. There are few dishes that couldn't benefit from a squeeze of lemon juice, or a pinch of zest!
A sprinkle of lemon juice perks up roasted vegetables, is an invaluable partner to seafood and adds complexities to fats such as butter.
Lemons will keep at room temperature upwards of a week. In the refrigerator, they'll last up to three weeks in dry and sealed conditions. Lemon juice, however, will freeze for about a year.
Lemons are a great alternative to chemical cleaners. Yes, you can clean with lemons! The low pH of lemons means the juice is antibacterial. It can also deodorize, disinfect and cut through grease. Here's a recipe for homemade lemon cleaner.
Stretching your food dollars through preservation
While lemons won't last more than a few weeks in your kitchen, there are many ways to preserve a bumper crop. The first, obviously, is freezing the saved juice in ice cube trays where it can be later added to recipes. Or you can freeze it in larger quantities to make lemonade.
Countries where lemons are native have a culinary tradition of preserving them. In Morocco, lemons are preserved whole in a mixture of brine and lemon juice. In India, lemon pickle is often served as a condiment. You can even preserve lemon zest, which when dried turns to a spice you can add to dishes.
The lemon so often plays a supporting role in cooking that it's refreshing to see them in a recipe where they can stand out, like these classic lemon bars. The recipe below is an adaption of Ina Garten by way of Smitten Kitchen and is a perfect way to perk yourself up out of the winter doldrums.
For Shortbread Crust
1/2 pound unsalted butter, at room temperature
1/2 cup granulated sugar
2 cups flour
1/8 teaspoon kosher salt
For Lemon Filling
6 extra-large eggs at room temperature
2 1/2 cups granulated sugar
2 tablespoons grated lemon zest (4 to 6 lemons)
1 cup freshly squeezed lemon juice
1 cup flour
Confectioners' sugar, for dusting
1. Preheat the oven to 350°F and grease a 9 x 13 by 2-inch baking pan. Or you can use a Pyrex dish, which totally works.
2. To prepare the crust, cream the butter and sugar with electric mixer fitted. Combine the flour and salt and, with the mixer on low, add to the butter until just mixed.
3. Gather up the dough in a ball and place in the greased baking dish. Using your hands, gently press the dough into the bottom of dish, creating an even layer. Dough should be about a half inch thick. Chill the dough for an hour. This part is important.
4. While the dough is chilling, whisk together the eggs, sugar, lemon zest, lemon juice and flour in a bowl and set aside.
5. When the dough is ready, bake the crust for 15 to 20 minutes, until very lightly browned. Let cool on a wire rack. Leave the oven on.
6. Pour your filling mix over the crust and bake for 30 minutes, or about five minutes beyond the point where it is set. Be careful not to overcook, as the filling will become gummy. The bars should be lightly golden, not dark brown along the sides, which is a sign of over baking.
7. Let cool to room temperature. Cut into rectangles and dust with confectioners' sugar.
(*Real Food rule of thumb: We think that first and foremost, in terms of nutrition, people should eat lots of fruits and vegetables whether they are organic or not. The EWG's guide is a handy list, but we will point out here that the impacts of pesticides are not limited to your ingestion of them -- agricultural chemicals also affect farmworkers and local waterways, both good reasons to buy organic, even those vegetables that carry a light pesticide load. Also, it has been demonstrated that produce grown by small-scale farmers, even those who are not certified organic, tends to have a lighter pesticide load than its industrially-produced counterpart, owing to industry's tendency toward large monocrops.)
This post was originally published in January 2014.