Jalapeño Peppers

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Key Factspending-external-review

  • The majority of the U.S. commercial jalapeño supply is grown in New Mexico, Texas, and California but many small farms throughout the southwest grow peppers for sale to local markets. Jalapeños are also imported to the U.S. and imported peppers were the source of a large Salmonella Saintpaul outbreak in 2008.      
  • Peppers are often an ingredient used in making fresh salsa and guacamole and their role in foodborne illness outbreaks may not have been fully credited in the past. Between 1973 and 2008, 136 salsa- or guacamole-associated outbreaks were reported with over 5600 total illnesses.
  • During the growing season, a pepper plant will be harvested multiple times overall, producing about 25 to 35 pods per plant.
  • Pepper pungency is rated in terms of ‘Scovolle heat units” and jalapeños can range from 2,500 to 10,000 Scoville units.
  • Chipotles are ripened jalapeños which have been smoked and much of their moisture removed. Jalapeños seeds are called picante and are used to add a spicy flavor to many cuisines.


The jalapeño pepper is a medium-sized chili pepper. A mature jalapeño is the length of 2-3 inches and is typically picked and consumed while still green. Occasionally they are allowed to fully ripen and turn red in color. Capsicum is derived from the Greek word, kapos, “to bite”. The heat comes from a group of alkaloid chemicals called capsaicinoids, principally capsaicin and dihydrocapsaicin. These oily compounds are very soluble in fat and alcohol, but insoluble in water.

Jalapeños are rich in vitamins A and C, contain carotene (an antioxidant), and have been shown to reduce cholesterol and triglycerides. Capsaicin is also used for relieving pain from shingles (Herpes zoster) and diabetic nerve degeneration. The heat produced from the capsaicin triggers the hypothalamus gland to begin cooling thus, capsaicin is used as a natural cooling agent when applied exteriorly. Capsaicin ointments are available for the relief of sore muscle and arthritis pain.


The basic anatomy of a jalapeño pepper includes the placenta or the capsaicin glands. Capsaicin is produced by the glands between the placenta and the endocarp. The highest concentration of the capsaicin is found closer to the seeds of the pepper. However contrary to popular belief, the seeds themselves do not produce capsaicin, but can absorb some capsaicin. The exocarp is the outer layer of the pepper known as the skin. The mesocarp is located in the center of the pepper and holds most of the absorbed water while also providing structural support for the pepper. The endocarp is the membrane layer surrounding the seeds of the pepper. The seeds are an edible part of the pepper however they contain little capsaicin and are not a contributor to the flavor profile. The calyx or crown is where the pepper sprouts and the pod begins to develop. This area of the pepper is normally dry and leaf like, the connector between the flavorful pepper and the stem. The apex has the least amount of capsaicin and thus contributes the least amount of heat.

Scoville Scale (Heat)

The Scoville scale is a measurement of heat or pungency, named for an American pharmacist Wilbur Scoville. The Scoville test was designed in 1912 to measure the capsaicin sensitivity of testers. The Scoville heat unit (SHU) scale is not precise but is a method to measure capsaicinoid concentration. Normal capsaicin concentration is estimated to be ~18mM/SHU. The actual assessment of the heat of a pepper is estimated by measuring the amount of alcohol extract of the capsaicin oil of the dried pepper. Panelists taste the pepper with varying additions of sugar and water to determine the difference between the heat of peppers until the heat is barely detectable. The degree of dilution is then used to measure with the Scoville scale. Thus, a sweet pepper or bell pepper containing no capsaicin at all has a Scoville rating of zero meaning no heat is detectable.

 Common Jalapeño Varieties

Señorita Jalapeño
Señorita Jalapeño

The Señorita jalapeño pepper appears dark green in color, eventually turning purple and finally red when left on the vine until mature. The plant grows to nearly 2 feet high. The pepper pod typically grows three inches long and one and a half inches wide. The maturity period for these peppers is eighty days from seed to harvest. The Señorita pepper is very hot and typically registers 5,000 SHU on the Scoville scale.

Fresno Chile
Fresno chili variety.
Fresno chili

The Fresno Chile jalapeño pepper is closely related to the Señorita pepper. However, it takes less time to grow to maturity and produces smaller, milder fruit. The peppers are small in size measuring only about 2 inches in length. On the Scoville scale these peppers are registered as mild reaching only 300-400 SHU.

Sierra Fuego

The Sierra Fuego jalapeño pepper is a hybrid which produces a large amount of peppers per plant. This pepper measures 3.5 inches long and 1.5 inches wide when mature, which typically takes 80 days. The pepper is mildly hot and grows from dark green in color to red with maturity.

Sierra Fuego variety.
Sierra Fuego
Mucho Nacho

The Mucho Nacho jalapeño pepper is a fast maturing hybrid. The plant can reach full maturity in sixty-eight days, from seed to harvest. The peppers from this plant are longer in length, about 4 inches. This pepper is known for its large size and flavor without extensive heat.

Foodborne Outbreaks

Mucho Nacho variety.
Mucho Nacho

Jalapeño peppers are susceptible to microbial contamination via irrigation water or improper handling and have been implicated in foodborne illness outbreaks. Most notably, a Salmonella Saintpaul outbreak in 2008 was linked to raw produce, including jalapeño and serrano peppers, which involved more than 1500 cases of salmonellosis.  An outbreak of Type B botulism was linked to commercially canned hot peppers in 1973. It was determined peppers, which tend to be neutral in pH, were not properly acidified before processing. Peppers are often an ingredient used in making fresh salsa and guacamole and their role in foodborne illness outbreaks may not have been fully credited in the past. Between 1973 and 2008, 136 salsa- or guacamole-associated outbreaks were reported with over 5600 total illnesses.


Soil Preparation

Jalapeños and other hot pepper varieties grow best in a sandy loam soil, which is classified as soil consisting of approximately equal parts sand, silt, and clay. Well-drained sandy loam soil is ideal for growing warm-weather produce such as peppers, tomatoes, melons, and citrus. In addition to the texture and consistency of the soil, jalapeño producers also monitor the pH levels and soil nutrients (nitrogen, phosphorous, and potassium). Pepper plants grow optimally in slightly-acidic soil with a pH between 6.0-6.8. The soil can be supplemented with starter solutions of nitrogen, phosphorous, and potassium to ensure rapid growth after the transplantation. Plants that do not grow rapidly enough will begin to bloom and fruit set, leaving small or stunted plants. Stunted plants will not produce as large of yields, and can be less robust against the weather.

Planting and Irrigation

Jalapeño seedlings one week after planting.
Jalapeño seedlings one week after planting.

Jalapeños peppers can be planted using two different methods, direct seeding or transplanting. There are two planting seasons for producing jalapeños, a spring period (March-April) and a fall period (late July-August). Direct seeding in the spring should occur once soil temperatures are above 60⁰F, whereas direct seeding in the fall should occur approximately 120 days prior to the first frost. Transplanting, the more common of the two methods, should occur after the last frost in the spring and approximately 85-100 days prior to the first frost in the fall. Transplanting is often preferred over direct seeding due to easier weed control, more consistent fruit set, and reduced seed cost.

Prior to transplanting, jalapeño plants are typically grown in greenhouses. After about 4-6 weeks of growth, they are transplanted either by hand or machine into the fields. Transplanted peppers are often spaced 12-16 inches apart in rows with approximately 36 inches between. For direct seeding methods, seeds are planted in raised beds with an average of 2-6 inches between seedlings.

Jalapeño flower with fruit set.
Jalapeño flower with fruit set.

Pepper varieties are warm climate crops, and can be highly sensitive to extreme weather exposure.  Optimum fruit set yields the best when the temperature stays within the range of 65⁰-80⁰ F. Jalapeños and chili peppers tend to be more robust than bell pepper plants and can maintain proper growth and fruit set at higher temperatures. For jalapeño growth specifically, the combination of hot days (85⁰-95⁰F) with cool nights (65⁰-70⁰F) provides the optimal environment for high fruit yield.

Jalapeño crops require moderate to high amounts of watering, depending on the surrounding environment. In more humid areas, moisture stressing seedlings 25-30 days after planting can facilitate better root development. In drier climates, moisture stressing the seedlings might not have the same effect. For commercial jalapeño production, overhead and drip irrigation are the two most common methods used for watering crops. Proper irrigation is crucial to these warm climate plants to maintain consistent soil moisture. If under-watered, pepper plants can have a difficult time recovering from drought and can cause shedding of flowers and fruit. Over-watering can cause root-rotting and growth of plant harming organisms.

Harvesting and Handling

For spring jalapeño planting, harvest will occur in June. For fall planting, harvest will begin in October and last until the first frost. Time until harvest will also varying depending on whether jalapeños were grown through direct seeding or transplanting. Harvest for direct seeding crops will occur approximately 110-120 days after planting, whereas transplanted crops will be ready after approximately 75-85 days. Fully mature jalapeños should have a firm, glossy, green skin with solid pods approximately 2-2.5 inches in length. The AgriLife Extension at the Texas A&M Department of Horticulture advises that crop yield will be maximized if harvest is postponed until 5-10% of the fruit have turned red. Peppers are graded and divided into two categories: market grade versus processing grade. Market grade jalapeños are sold fresh in grocery stores and can be sold with stem. Processing grade jalapeños are required to have the stem removed. On average, 8-10 tons per acre of jalapeños and other hot pepper varieties can be harvested. To ensure integrity and quality of the jalapeño, it is necessary to maintain proper holding temperatures. Peppers are sensitive to injury if held in temperatures below 45⁰F. They can be optimally maintained at 50⁰-55⁰F in 80% humidity for 2-3 weeks.

For more information regarding the production and distribution of Jalapeño Peppers please visit the Produce Point of Origin Database.

Food Safety

Like any other fruit or vegetable, peppers can be contaminated by pathogens from the soil, water, animals, or human sources. Peppers need to be washed with cool, clean water prior to eating or preparing and dried with paper towels. Some commercially produced jalapeños may have a light food grade wax applied on the outside of the pepper to reduce moisture loss, prevent bruising during shipment and storage, and extend shelf life. This wax can be removed by lightly scrubbing.

Jalapeños should be stored wrapped in paper towels on an upper shelf in the refrigerator. Jalapeño peppers should last up to three weeks in this type of storage.

Halved jalapeños with seeds and veins.
Halved jalapeños with seeds and veins.

Jalapenos are susceptible to chilling injury; the optimal storage environment is 40-45°F (in a commercial setting but stored at 40°F or below in a retail or home refrigerator) and high relative humidity (90-95 percent). Jalapenos may over ripen and the skin will wrinkle.

Gloves should be worn while handling hot peppers. The eyes, nose, and mouth areas are prone to irritation from capsaicin content. If exposed to capsaicin while handling or preparing jalapenos, the area should be rinsed immediately with water or a milk soaked towel applied over the area. Additionally, the heat intensity of jalapenos can be lowered during preparation by cutting open jalapenos, removing veins and seeds. Soaking in salt water for at least one hour will decrease the heat even more.


Preference for chili peppers in the United States has continued to increase throughout the decade.  This increase in chili pepper consumption is driven by both changes in the American diet, desire for new flavors, and overall diversification of the population.  From 1995 to 2005, the consumption of chili peppers has increased by 38% from an average of 4.3 pounds per person in 1993-1995 to 5.9 pounds per person in 2003-2005.

More information on keeping peppers stored safely can be located at FoodKeeper App.


The nutritional properties of peppers range greatly depending on the variety and maturity. One cup of sliced raw jalapeños is considered to be a serving and contains only 27 calories, mostly from carbohydrates and some protein. There are also vitamins and minerals in one serving of jalapeños including 14% of the daily requirement of Vitamin A, 66% Vitamin C, 1% Calcium and 4% Iron. Red peppers contain lycopene and have been shown to reduce the risk for certain types of cancers. Red peppers are also a source of vitamin B6. Bell peppers have a high concentration of beta-carotene which has been shown to reduce the risk for macular degeneration and cataracts. Green peppers also contain fiber, folate, and Vitamin K.





Kathryn McCullough

Kathryn McCullough

Megan Webb

Megan Webb

Marisa Bunning

Marisa Bunning

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