All About Chilis

How hot is that chile?

chile peppers If you like to cook with chile peppers–and so many people do these days, given the popularity of such spicy cuisines as Mexican, Asian, and Caribbean–you’ve probably heard of the Scoville scale. Chile aficionados will brag that their favorite chiles are the hottest, with a scorching 300,000 on the Scoville scale, while that jalapeño you’ve just learned to love only measures a wimpy 4,000. But what exactly do these numbers mean, and how do they translate into useful information?

Scoville took the guesswork out of judging chiles. Let’s start with the invention of the Scoville scale, and then we’ll look at how different varieties of chiles rank in this heat hierarchy. In 1912, a man named Wilbur L. Scoville was working for a company that made an ointment for aching joints in which capsaicin, the heat-causing compound in chiles, was an important ingredient. The company was constantly frustrated because the heat level in chiles varied so much. Scoville devised a formal test in which exact weights of chiles were dissolved in alcohol and then added to sweetened water in precise measures. Tasters were asked to determine how much water was needed to neutralize the heat. A rating number was assigned, according to how many units of water were added before the chile’s heat became imperceptible.

Scoville’s test was used for the next six decades, yet it wasn’t totally reliable, given the fact that human testers’ palates are different and easily fatigued by repeated tastings of hot food. In 1980, a more objective test was introduced, the High-Pressure Liquid Chromatography Test, in which powdered chiles are dissolved and then analyzed through a light beam that shows the heat compounds as fluorescent. Most large producers use this test today, but because the Scoville name has been so deeply ingrained in the industry, they make a conversion and still express the pungency in Scoville units.

The Scoville scale ranks fire but not flavor. So what does any of this have to do with the flavor of chiles? Not much. These tests isolate only the heat-causing compounds, but tell us nothing about the overall flavor. The heat of a chile is found in the inner membrane, while the flavor comes from the meaty pod itself and makes all the difference in how we experience the heat. These tests also do nothing to discern how the heat is felt. As anyone who has eaten a lot of chiles will tell you, some, such as the habanero, deliver sharp, quick bursts of heat, while others, such as the fiery red Thai pepper, burn and linger. Some hit you up front on the lips and tip of the tongue, while others scorch your entire mouth and throat. Even the researchers themselves will admit that for all their accuracy, the pepper is a fickle plant: its heat varies widely from pod to pod, plant to plant, garden to garden, and season to season. Even on a single bush, a pod from the sunnier side will be hotter than one from the shady side. A quick look at a sample Scoville scale (right) shows the wide variances within each type of chile.

The Scoville rating provides a good general measure of the relative heat of different chiles. In other words, you can be assured that a cayenne will be hotter than a poblano. But ultimately, taste remains a subjective experience. There’s no substitute for breaking open a chile and tasting it yourself (carefully) for flavor and, of course, for firepower.

The Right Techniques for Fresh Chiles

Fresh chiles are becoming more available all the time, and few supermarkets are without the ubiquitous jalapeño. But the range in quality can be discouraging, and it can be difficult to distinguish fresh chiles from ones that have been on the shelves a while. When shopping for fresh chiles, look for those with smooth, tight skin and a thick, meaty body. A fresh chile should have some heft relative to its diminutive size.

If you won’t use your chiles right away, keep them cool and dry. You can refrigerate them, but be sure to first remove them from the plastic produce bag; otherwise, they’ll be-come soft and moldy. The length of time that chiles will stay fresh in the refrigerator depends on how fresh they were when you bought them, but generally they’ll keep for three or four days without suffering any loss of freshness. Once the chile’s skin begins to wrinkle, it will lose some of its potency, and if you’re roasting or blanching them, the skins will be difficult to peel.


Unless you have particularly tough hands, it’s a good idea to use rubber gloves when handling fresh chiles. Many cookbooks recommend using dishwashing gloves, but I find that these are rather clumsy and that getting a handle on small chiles while wearing them can be frustrating. Instead, I like to keep a few pairs of surgical gloves around the kitchen. Available at most drugstores, surgical gloves are cheap, disposable, and best of all, they allow you to get a firm grip on the chiles. Once you’ve begun working with the chiles, be extremely careful not to touch any part of your body, especially your eyes. After you’ve finished, wash your knife and cutting board with hot soapy water.

Preparing & cutting chilesProtection with a grip. Surgical gloves protect sensitive skin from chiles’ painful sting, and they
improve your grip.

Capsaicin is the chemical compound that gives chiles their heat. An alkaloid, capsaicin is distributed throughout the chile, but the heaviest concentration of capsaicin is found in the white pith on the inside of the chile–those ribs that hold the seeds in place. Further down on the scale of concentration are the seeds and then the chile’s flesh, which has the least amount of capsaicin. This gives you a convenient way of controlling the amount of heat that the chile contributes to a dish. To get the most bang out of the chile, use it whole; for a milder flavor, simply trim out the seeds and ribs.


Start by cutting off the entire stem, and then slice the chile in half lengthwise. With the tip of a paring knife, you can remove the seeds and ribs by slicing or nudging them with the knife point. With seeds and ribs out of the way, the chiles are easily cut into strips or a fine dice.

Stemming and seeding
a chile.
After removing the stem, slice the chile lengthwise to expose the seeds and ribs. Remove the seeds and ribs to moderate the heat, or leave them in for extra punch.


Many dishes, especially Mexican and Southwestern recipes, call for the chiles to be peeled. You can do this by first charring or blanching the whole chiles. To char, rub them with a little oil and then set them directly over a gas burner. Turn the chiles frequently with tongs or a fork to prevent burning through to the flesh. When the skins have charred and blistered slightly, pop the chiles into a plastic bag and let them steam in their own juices for about 20 minutes. The skins should now rub off easily.

Blanching chiles won’t give you the smoky flavor that charring does, but the technique is great if you don’t have a gas stove. Simply drop the chiles into boiling water for 30 seconds or so, and then plunge them into ice water. Once the chiles have cooled, they can be skinned just as if they were charred.

Drying chile peppers

Drying chiles is one of the best ways to preserve your harvest, but be sure to dry them when they’re fully ripe for the finest flavor. For poblanos, this means when they turn bright red. Any type of chile can be dried by one of the following methods, except for jalapeños, which do best when they’re smoke-dried (turning them into chipotles). Don’t try drying chiles with black spots; they’ll turn moldy and rot. Dried chiles

If you live in a dry climate, the simplest way to dry the chiles is to tie them on a string by their stems, in clusters of three, and hang them in the sun. This is called a ristra. When the pods are dry but still pliable (this could take weeks, depending on the heat and humidity), hang them indoors and out of direct sunlight to finish drying.

In areas of high humidity, the chiles might rot before the sun can dry them, so your best bet is to halve them lengthwise and use the oven (or a food dehydrator). In a gas oven, set the halved chiles directly on a baking sheet and dry them using just the heat from the pilot light. This may take a couple of days or longer. In an electric oven, the chiles will dry much faster. Set the oven to low, about 175°F, and check the chiles every
few minutes to make sure they don’t burn.

The chiles are fully dry when they snap, not just bend. Store them in sealed glass jars in a cupboard, or in the freezer double-wrapped in freezer bags. (Don’t put bagged chiles in a cupboard because the plastic is porous and the chiles can oxidize, ruining both the color and the flavor.) With both storage methods, dried chiles last indefinitely.

To reconstitute the chiles, soak them in hot water for about 15 minutes, fry them in a bit of oil until they puff up, or lightly roast them. Dried chiles can also be ground to a powder when you’re ready to use them (no earlier, because the powder would lose its flavor).