There is a bewildering array of chile peppers available to us at the supermarkets (and farmers’ markets later in the summer) varying from mild to hot to extremely hot. Not knowing the difference can result in a surprisingly spicy dish when we just want a little “kick.”
Chile refers to an individual species of pepper, while chili is usually a blend of peppers varying in heat and flavor. Chili is usually dried, and bought as chili powder, usually includes mild paprika and cumin as part of the flavor package.
Generally speaking, the larger the pepper, the milder the flavor. Heat is measured in Scoville units, with quite a range variation in heat within a particular variety of pepper. For instance, the jalapeño usually varies from 1000-20,000 units. So take a tiny taste before using in a recipe so you can use the desired amount, avoiding surprises. I once made a pot of chili that was so hot we Gringos could hardly eat it!
So long, thin Anaheim peppers in the upper right of the photo are fairly mild, a form of New Mexico chiles often called Big Jim or Sandia. They are used in salsas, rice dishes, enchiladas and burritos, and often stuffed. They are usually harvested while green, then used in various preparations including Pork Green Chile or in Chiles Rellenos recipes. When allowed to ripen to red, they are typically dried and ground into a powder.
Fist-sized Poblano or Pasilla (pronounced pah-SEE-yah) peppers found in the upper left of the photo are dark green and wrinkled, and vary in heat from mild to medium hot. They are often stuffed with fillings that might include cheese, pork and raisins.
Smaller chiles include jalapeño chiles, Serrano, Habañero, Fresno, Shishito, and Thai Bird chiles.
Jalapeño peppers nestled just below the Anaheims in the photo are medium sized, deep green in color ripening to orange and red, and grow point down hanging from branches. When allowed to ripen to red, they are often dried and smoked, called chipotle chiles. When ground, they become chipotle powder, which I use often for the deep smoky flavor that adds character to lots of dishes.
Serrano chiles in the lower left of the photo are thinner than jalapeño peppers, the same rich green color, and the same length, but usually hotter. They range from 10,000-25,000 Scoville units. I like them sliced very thinly and added to sauces.
Fresno chiles are red with a pointed end rather than a rounded end as compared to a ripe red jalapeño. They grow point up instead of point down. They usually range from 2500-10,000 Scoville units. I use them when I want their beautiful red coloring.
Habañero peppers are usually orange, and range from 100,000 -350,000 Scoville units, so be careful when using them. I’m a wuss when it comes to heat, so I almost never use them raw. But I love the Habañero-Garlic sauce made locally by Gilbertos Gourmet Goodness. I just use it sparingly to add desired punch to recipes rather than Tabasco.
Thai Bird chiles (not pictured) are Asian, very hot, usually varying from 100,000-225,000 Scoville units. They are antibacterial and used topically to clean wounds and prevent infection in India, interestingly. Not often found in markets here, but they can be grown if you like them in recipes. I usually slice them very thinly to add raw to sauces and as garnishes to salads and soups. A comparable Mexican chile is the Chile de Arbol, often found dried.
The latest popular pepper is Japanese, a Shishito pepper, usually found green but ripening to orange and yellow, sometimes red. These are sweet peppers, usually lightly roasted and blistered and tossed with Sesame oil and Tamari for a delicious snack, eaten whole. They are pictured in the photo just below the jalapeño chiles in the lower right corner.
Hope this helps straighten out confusion regarding heat levels in chile peppers. Have fun experimenting with them!