Jalapeno Striations

• As jalapenos age and grow hotter, they develop lengthwise striations. These lines look like a cracked outer skin, but the pepper may be smooth to the touch despite its appearance. Striated skin may occur on both red and green jalapenos and is an indication of heat in both. Support for the idea that jalapenos with striated skins are hotter than jalapenos with smooth appearing skin is mostly anecdotal, but the assessment is widely shared among farmers and chefs.

Jalapeno Color

• Although researchers have not documented this widely held belief, many cooks and farmers attest that red jalapenos tend to be hotter than green ones. Jalapenos redden as they ripen and also grow hotter as they age, so the redness and heat may both be consequences of the pepper aging process rather than the redness causing the heat or vice versa. Red jalapenos also have brighter flavor than green ones.

Sourcing Consistency

• Retail stores tend to buy their jalapenos from the same sources over time, so if you know that one store or produce stand tends to carry hot jalapenos, you can expect the jalapenos you purchase there to be hot. Similarly, farmers' market vendors who grow jalapenos may save their own seeds or maximize variables such as sun and heat that make their jalapenos hot. Rely on past experience when selecting jalapenos for heat or avoiding peppers that may be intimidatingly hot.

Time of Year

• Because jalapenos get hotter as they age, there's a good chance you'll get hotter jalapenos in September than in July in most temperate climates. However, if you buy jalapenos at a grocery that buys them wholesale grown in warmer climates, it's more difficult to determine whether they were harvested early or late in their growing cycle. In fact, if you're in the Northern Hemisphere and buy peppers grown in the Southern Hemisphere, you could be buying jalapenos grown during summer although you're currently experiencing winter.