Are green chilies hot or not?

January 12, 2026 •

4 min read

With over 4,000 varieties of chili peppers in existence, it is a common misconception that all green chilies possess the same heat level. In reality, the term 'green chili' is a broad, overarching category, encompassing a vast range of peppers with vastly different flavor profiles and heat intensities, from very mild to mouth-searing hot.

Quick Summary

The heat of a green chili varies dramatically by variety, with some being mild and others intensely spicy. Heat is determined by the chemical capsaicin, and its concentration is affected by genetics, ripeness, and growing conditions.

Key Points

Variety Determines Heat: The heat of a green chili depends entirely on its specific type, ranging from very mild Anaheims to extremely hot Thai Bird's Eye chilies.
Capsaicin is the Source: The burning sensation is caused by capsaicin, a chemical compound concentrated in the pepper's veins and pith, not its seeds.
Ripeness Matters: Green chilies are typically unripe. As they mature and change color, they generally increase in heat, though this isn't a universal rule.
Growing Conditions Play a Role: Environmental factors like temperature, water, and soil can stress the plant and affect its capsaicin production, influencing the final heat of the pepper.
Appearance is Not Reliable: You cannot accurately judge a green chili's heat by its size, color, or other visual cues alone.

The Science Behind a Chili's Heat

The burning sensation you experience when eating a chili is not a taste but a pain signal triggered by a chemical compound called capsaicin. Capsaicin is produced by the chili plant as a defense mechanism against mammals. The intensity of this compound is measured using the Scoville Heat Unit (SHU) scale, developed by chemist Wilbur Scoville in 1912. The higher the SHU, the greater the concentration of capsaicin and the hotter the pepper feels. While capsaicin is found throughout the pepper, the highest concentration is located in the placenta and veins, the white pithy membranes that hold the seeds, not the seeds themselves.

Mild and Medium Green Chili Varieties

Not all green chilies are created equal, and many popular varieties offer a mild to moderate heat perfect for a wide range of dishes.

Anaheim Peppers (500–2,500 SHU): Also known as 'New Mexican' or 'California' chilies, these are one of the mildest green chilies available. With a slightly sweet, earthy flavor, they are excellent for roasting, stuffing (chiles rellenos), and incorporating into salsas.
Poblano Peppers (1,000–1,500 SHU): These large, dark green peppers are known for their rich, earthy flavor and relatively mild heat, which can sometimes vary. They are a classic choice for dishes like chiles en nogada and are often used when dried and called 'ancho'.
Hatch Green Chilies (1,000–8,000 SHU): Grown in New Mexico's Hatch Valley, these peppers have a distinct smoky, earthy flavor. Their heat level varies by variety, ranging from mild to extra hot, making it important to know which specific Hatch pepper you are using.
Shishito Peppers (100–1,000 SHU): These small, wrinkled peppers are known for a mild, slightly sweet flavor. Interestingly, about one in ten shishitos is hot, a surprise some diners appreciate.

Hot and Fiery Green Chili Varieties

For those who prefer a more intense kick, there are several green chilies that deliver a significant amount of heat.

Jalapeño Peppers (2,500–8,000 SHU): Perhaps the most famous green chili, jalapeños offer a versatile heat that complements a variety of dishes. They are common in Mexican and Tex-Mex cuisine and are often used in salsas, nachos, and stuffed poppers.
Serrano Peppers (10,000–23,000 SHU): Smaller and narrower than jalapeños, serranos pack a more significant punch. Their bright, crisp flavor makes them a popular choice for salsas and sauces.
Thai Bird's Eye Chilies (50,000–100,000 SHU): These tiny, slender chilies are known for their intense, building heat. A staple in Asian cuisine, they should be used with caution due to their high capsaicin content.
Habanero Peppers (100,000–350,000 SHU): While most are orange or red when ripe, green habaneros are also common. These are very hot and possess a fragrant, fruity flavor, popular in Caribbean and Central American dishes.

Factors Affecting a Chili's Heat

Several elements can influence how hot an individual green chili will be, even within the same variety.

Growing Conditions

Environmental stress, such as high temperatures, limited water, or poor soil quality, can cause a chili plant to produce more capsaicin. Conversely, plants grown in optimal conditions with consistent watering and moderate temperatures tend to yield milder peppers. This is why a jalapeño from a greenhouse might be milder than one grown in a hot, arid field.

Ripeness and Maturity

Generally, chili peppers increase in heat as they mature. This means a green chili, which is essentially an unripe pepper, will often be milder than its fully ripened red counterpart. However, this is a generalization and depends heavily on the specific variety. For example, a young, green Thai chili can still be significantly hotter than a ripe, red Anaheim.

Telling Heat Levels by Appearance

While some theories suggest you can predict a jalapeño's heat by its “stretch marks,” this is not a reliable method for all green chilies. Relying solely on a pepper's color, size, or texture is not an accurate way to gauge its spice level. The only way to know for sure is to rely on variety-specific knowledge or to taste a small amount.

Comparison Table: Green Chili Varieties by Heat


Variety	Scoville Heat Units (SHU)	Flavor Profile	Common Uses
Anaheim	500–2,500	Sweet, earthy	Roasting, stuffing, sauces
Poblano	1,000–1,500	Earthy, mild	Chiles rellenos, stews
Jalapeño	2,500–8,000	Versatile, grassy	Salsas, nachos, poppers
Serrano	10,000–23,000	Bright, clean	Salsas, sauces, marinades
Thai Bird's Eye	50,000–100,000	Intense, sharp	Curries, Asian dishes
Habanero	100,000–350,000	Fruity, fragrant	Hot sauces, marinades

Conclusion: The Final Verdict

The question of whether green chilies are hot is not a simple 'yes' or 'no' but a case-by-case evaluation. It is crucial to identify the specific variety of green chili in question and understand its typical heat range on the Scoville scale. Factors like growing conditions and ripeness can also play a role, introducing variability even within a single variety. By familiarizing yourself with the different types of green chilies, from mild Anaheim to fiery Thai Bird's Eye, you can confidently choose the right pepper to achieve your desired flavor and heat level in any dish. The world of green chilies offers a spectrum of flavors, and the spice-adventurous chef can explore them all with a little bit of knowledge about what to expect. For a deeper dive into the science of capsaicin and the history of the Scoville scale, visit the Wikipedia page on chili peppers.

Frequently Asked Questions

The heat level depends on the variety of the chili. Different types, such as Anaheim, Jalapeño, and Thai Bird's Eye, have different genetic makeups that determine their capsaicin concentration and, therefore, their heat.

The Scoville scale measures the concentration of capsaicinoids, which are the chemicals responsible for a chili's heat. It is used to rate the pungency of various green chili types, helping to quantify their spiciness.

No, this is a common myth. The majority of the heat-producing capsaicin is located in the white pithy membranes, or veins, that hold the seeds. While seeds can absorb some capsaicin, they are not the main source of heat.

Unfortunately, no. A pepper's appearance, including its size, color, or "stretch marks," is not a reliable indicator of its heat level, which is more dependent on variety and growing conditions.

Not necessarily. While a red chili is a ripened version of a green one and can sometimes be hotter, it depends on the specific variety. A hot green chili variety can be much spicier than a mild red one.

When a chili plant experiences stress from factors like limited water or high temperatures, it produces more capsaicin as a protective response. This results in a hotter pepper.

Anaheim peppers are a great choice for mild heat. They are long, bright green, and have a slightly sweet, earthy flavor. They are perfect for roasting or stuffing.