About Peppers (Capsicum sp.)
Peppers appear to have played a role in the diet (and cultures) of the Americas since as early as 7500 BCE, and have been in cultivation for at least 6,000 years. Not surprisingly, a rich culture surrounding peppers developed in places like Mexico, and throughout South America, where they have been in use for so many centuries. They were not known elsewhere in the world until Columbus returned with them to Spain in 1493.
Once the Spanish had colonized Mexico, peppers spread to the Philippines, and then to China. Chilies were introduced to India via the Portuguese colony at Goa. It’s notable that prior to this time, there were no chilies in Indian or South Asian cuisine. By 1650, peppers had spread to the Middle East, Africa, and elsewhere. There are now at least 3,000 named types of chilies and other peppers.
At the time of European contact with the Americas, black pepper (derived from the unrelated genus Piper) was an expensive condiment. The word “pepper” was used to describe anything hot. Peppers are broadly divided into two groups; Chili peppers and bell peppers. Both are members of the genus Capsicum, which belongs to the family Solanaceae, making them relatives of tomatoes, potatoes, and eggplants. As with tomatoes, the fruit of a pepper plant is technically a berry.
In most of the world, chilies are the preferred type of pepper. Bell peppers were bred to be free of capsaicinoids, the substances that gives chilies their heat. Bell peppers and many of the chilies are members of the species Capsicum annuum, but chilies are also represented by other species including C. frutescens (Tabasco and Thai), C. chinense (habanero and Scotch bonnet), C. baccatum (friar’s hat) and C. pubescens. In a very general sense, the chilies of C. annuum have a wide range of flavours, from grassy to sweet to smoky. C. frutescens deliver pure heat with less range in flavours. And C. chinense can have very fruity undertones, detectable beneath the searing pain they cause. Many cooks of Caribbean food will say, it’s not about the heat, but the flavour their chilies impart.
Bell peppers are often eaten while immature, when they are green, but all varieties will ripen to another colour, and the spectrum now includes red, yellow, orange, white, pink, purple, and brown. As bell peppers ripen, they develop more sweetness and more vitamin C. Green peppers have been described by some people to have a “grassy” flavour, and are not universally appreciated. Many chili peppers are also eaten while green and unripe as well, notably jalapeño chilies.
Chili peppers, of course, are used because of they contain capsaicinoids. The most notable capsaicinoid is called capsaicin, a crystalline substance found almost entirely in the pithy flesh that holds the seeds in place inside the chili. The seeds and skin contain very little, if any, capsaicin. When eaten, capsaicin is detected by heat receptors in the mouth, and the brain responds as though something hot (in terms of temperature) has been consumed. This increases the heart rate, causes perspiration, and the release of endorphins into the blood stream. The result is that (for those that like chilies) the heat “feels good.”
In 1912, American chemist Wilbur Scoville devised what he called the “Scoville Organoleptic Test” as a means to measure the relative hotness or piquancy of chili peppers. Although it is somewhat subjective, the Scoville Scale (as it is known) is still used by growers and makers of hot sauce to rate piquancy by so-called Scoville Heat Units (SHUs).
Scoville would mix the extract of each chili with corn syrup or a solution of sugar and water, and then a panel of five or six independent observers would taste the solution. If they still detected any heat, more sugar syrup would be added – over and over until the rating was 0. Scoville would then judge by what percentage the peppers needed watering down to reach this point. Bell peppers, which contain no capsaicin, have a Scoville rating of 0, while very hot peppers have ratings in the 100,000 to 350,000 SHU range. Scoville’s ratings, it should be noted, were largely based on the spiciness of dried chilies. Raw chilies are less spicy by approximately one order of magnitude. Pure capsaicin is considered to rate 15 million to 16 million SHUs.
Capsaicin is not water soluble, so the best way to reduce the burning sensation in the mouth is to consume dairy products like milk or yoghurt. Milk contains a phosphoprotein that acts as a detergent allowing capsaicin to be washed away. Many studies have been performed on capsaicin and its effects on human health. It seems to play a role in regulating the production of insulin, in the conversion of bad cholesterol, and in weight control for people who are obese. Capsaicin has also been seen to kill cancer cells in laboratory rats.
Chili peppers range from mild to extremely hot. Jalapenos are a good representation of medium heat. Thai Dragon, habanero, and Scotch bonnet chilies are much hotter than jalapeños, while anchos are comparatively mild. In the northeast of India grows a naturally occurring hybrid between C. chinense and C. frutescens, known as the bhut jolokia or Ghost Chili. This little three-inch devil is considered to rate an astonishing 850,000 to 1 million SHUs – some 400 times hotter than Tabasco Sauce, making it one of the hottest chilies ever known. Indeed, the government of India has grown the plants for use in weapons research. At the time of writing, the world record holder for heat is the Carolina Reaper, a hybrid between the Pakistani Naga and the Habanero. It weighs in at a modest 2.2 million SHUs. *
The heat from chili peppers is sensed in the mouth by the receptor protein TRPV-1, which is also responsible for sensing physical heat and pain. The brain receives the pain from capsaicin in the same way it detects when you’ve taken a drink of too-hot tea. But the heat of chilies has more subtle characteristics as well. The heat can be sudden, detectable as soon as a chili is bitten, or it can build. Thai Dragons and their cousins the bird chilies deliver immediate heat, but the habanero takes a moment and then explodes with heat. The heat may also be detected at the tip of the tongue or elsewhere in the mouth. And the duration of the burn can also vary from chili to chili.
Many evolutionary biologists feel that the presence of capsaicinoids in chilies is the result of co-evolution with birds, for birds lack the pain receptors that mammals have, so they do not feel any pain when they eat chilies. The small fruits are nutritious, but the seeds can pass through the gut of a bird unharmed, which makes the bird a very useful means of seed distribution.
In much of the world, food laced with spicy chilies is simply part of the daily routine. In the West, though, the novelty of chilies has led to a vast array of hot sauces. Whole retail outlets can be found that sell only hot sauces and foods that celebrate the chili pepper. Chili con carne is such a popular dish in America, and chili cook-offs have become so ubiquitous that they are now sanctioned by the non-profit International Chili Society.
Chili festivals abound in North America, but perhaps Hatch, New Mexico (which dubs itself the Chili Capital of the World) takes the prize with its annual Hatch Chili Festival, a two-day event in early September that has been running for nearly 40 years. The list of events features live music, a horseshoe tournament, a parade, a charity auction, a rope and bullwhip show, a chili toss, and of course, a chili eating contest.
How to Grow Peppers:
Difficulty: Easy, but an early start is essential. Peppers work well in large containers.
Timing: Peppers need warm temperatures and a long growing season. Start indoors 5-8 weeks before last frost, or in early March on the coast. Transplant when weather is really warm in early June or later. Transplanting early does not make the weather heat up!
Sowing: Sow indoors 1cm (½”) deep. Keep soil as warm as possible: 27°C (80°F) is best, until germination. Seeds sprout in 8-21 days depending on soil temperature. Try to keep seedlings at 18-24°C (64-75°F) in the day, and 16-18°C (61-64°F) at night. Avoid night temperatures below 12°C (55°F). Pepper seeds make take up to three weeks to germinate, so be patient.
Soil: Soil should have abundant phosphorous and calcium, so add lime and compost to the bed three weeks before transplanting. Aim for a pH of around 6.5. Mix ½ cup of complete organic fertilizer under each transplant. Too much nitrogen will produce an abundance of leaves, but fewer fruit. Though peppers will tolerate dry soil, they will only make good growth if kept moist. Grow in full sun.
Growing: Harden off before planting in the garden in mid-June, 45cm (18”) apart. Water in transplants with kelp-based fertilizer. Using plastic mulch with a cloche can increase the temperature a few degrees, and every degree helps. Pinch back growing tips to encourage leaf production. This helps shade peppers and prevents sun-scald in hot summers.
Harvest: When fruit is firm it is ready to pick. But if you wait, the fruit will ripen further turning red, yellow, brown, or purple. The sweetness and Vitamin C content go up dramatically when the fruit changes colour. If you pick while they’re green, the total number of peppers harvested will increase. Fruit that sets after late August will usually not develop or ripen. Pull out the entire bush just before the first frost and hang it upside down in a warm, dry place to ripen hot peppers. Expect 5-10 large bell peppers per well-grown plant, and 20-50 hot peppers per plant.
Storage: Peppers don’t stay fresh and crunchy for more than a few days, even in the refrigerator, so use them while they are in season. Small chiles can be dried if laid on cookie sheets in an airy place. Pickling also works well for smaller peppers.
Seed info: In optimum conditions at least 65% of seeds will germinate. Soil temperature for germination: 24-28°C (75-80°F). Usual seed life: 2 years.
Growing for seed: Isolate individual varieties by at least 30m (100’) if growing for seed.
Pests & Disease: To prevent rot and wilt, plant in well-drained soils and follow a 4-year rotation. If cutworms are a problem, use paper collars at the plant base. Tobacco mosaic virus (TMV): Young growth is malformed and leaves are mottled with yellow. To prevent it, wash hands after handling tobacco, before touching peppers. Control aphids which spread the disease.
Companion Planting: Pepper plants make good neighbours for asparagus, basil, carrots, cucumbers, eggplant, endive, oregano, parsley, rosemary, squash, Swiss chard, and tomatoes. Never plant them next to beans, Brassicas, or fennel.
*Update — Since writing this article, an even hotter chili has been discovered! Welsh plant breeder Mike Smith accidentally produced the Dragon’s Breath chili, that is estimated at 2.48 million SHUs!