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Why do Jalapeño Peppers Have Lines – And What Do They Mean?

When you go to the grocery store to purchase some Jalapeño peppers, have you ever noticed that some of them often have lines on them that look like cracks or stretch marks? And if you noticed them, have you wondered what they mean? Do the stretch marks indicate that this Jalapeño pepper is bad or about to go bad? Should you buy them, or pick an unblemished alternative?

The good news is these lines are completely safe and natural and do not mean that the pepper is bad or about to go bad. These lines are often referred to in many ways: stripes, cracks, stretchmarks, or corking. Regardless of what you call them, savvy home cooks and professional chefs actually prefer picking Jalapeños with cracks on them since they tend to be spicier and have more flavor – read on to find out why!

What causes the lines in Jalapeño peppers?

The thin vertical lines that develop on Jalapeño peppers are a form of scarring on the chili pepper pod. These lines are known as corking, because of their brown and beige coloring, which happens to look like a cork. Corking occurs when the inside of the Jalapeño pepper grows faster than the skin can stretch, causing the skin to split open to accommodate the pepper’s growing size.

Corking often tends to happen close to the stem, and then extend down the pepper. Corking frequently occurs after a long rain shower followed by prolonged sunlight. The combination of the two can lead to a growth spurt in the pepper leading to the signature stretch marks.

If you’re curious about pepper corking, I have an article covering the entire topic of pepper corking.

Infographic created by Spicy Trio highlighting what causes lines and cracks on jalapeño
Infographic displaying what causes the lines on jalapeño peppers. Created by Spicy Trio, feel free to share or use but please link back to us.

What colors are the lines in the Jalapeño peppers?

The lines that often develop on Jalapeño peppers, known as corking, can be white, beige, or brown in color. The lines change color from white to brown as they age and the longer the tiny cracks are exposed to the sun, the darker they become. They also become more prominent as the Jalapeño pepper ages, changing form a bright green color to dark green before turning red.

When is a good time to pick Jalapeños?

If you want your Jalapeños to be green and spicy, the best time to harvest them is when they are dark green, have grown large, and show signs of corking. If you want red Jalapeños, leave them on the plant until they change colors and watch as they go from dark green to bright red. Sometimes you will see a Jalapeño pepper that is half green and half red. This is because the pepper is halfway through the final stage of ripening when the entire pepper turns red.

Pro chef tip: Should you select Jalapeño peppers with lines when you see them at the store?

Interestingly, consumers in the U.S. find Jalapeños with lines or corking less desirable than those that have no blemishes. This is because many consumers in the U.S. see those lines as unsightly and a sign that the pepper could be starting to spoil.

This is unfortunate because some of the most flavorful and spicy Jalapeños are the ones that have significant corking on them. Often in the U.S., Jalapeños that have developed lines are sent to picklers and hot sauce manufacturers since they are less concerned about the aesthetics of the pepper, and consumers do not see the lines in the end products.

Even though the average consumer in the United States avoids picking Jalapeño peppers with signs of corking on them, there are some consumers that specifically look out for it. Professional chefs and experienced home cooks dig through the Jalapeño bins at the grocery store or market looking for the ones with cracks on them. This is because these ones are often spicier and more flavorful than non-cracked Jalapeño peppers. The reason why they are more flavorful and spicier is not from the corking, but because a Jalapeño pepper with corking is more likely to be a more mature pepper. The longer a Jalapeño pepper is on the vine, the higher the chances are that it will develop corking at some point during its growth cycle. This means that a Jalapeño with corking is more likely older and more mature than one without, and thus might have more flavor.

Outside of the U.S., many markets want to carry Jalapeños that have corking because local consumers see it as a sign of quality. This is common in Mexico and Latin American countries.

How to avoid corking in Jalapeño peppers and other chili peppers?

If you are unconvinced that corked Jalapeños are the best and still prefer a Jalapeño pepper without stretch marks, here are some gardening tips to growing an aesthetically pristine Jalapeño pepper.

When it comes to preventing corking in Jalapeño peppers, it all comes down to controlling a Jalapeño plant’s supply of water, sun, and nutrients. A sudden rainstorm followed by a lengthy period in the sun will most likely result in the Jalapeño pepper pods growing faster than the outer skin allows, leading to the splitting of the skin. Here are three ways to prevent rapid growth in Jalapeño peppers:

  1. Grow your Jalapeños in a greenhouse. A green house is the best way to control how much water and sun your Jalapeño pepper plants get which means you have greater control over how fast they grow.
  2. Put a tent or tarp over your Jalapeños if a rainstorm is coming. This will reduce the amount of water your Jalapeño plant absorbs over a short period of time.
  3. Do not overdo it with the fertilizer and nutrient mixes. A spike in nutrients can lead to rapid growth of the Jalapeño pepper pod, which in turn leads to an increased chance of corking.

Are Jalapeño peppers the only type of chili pepper that develops lines?

Nope, any chili pepper can develop lines and cork from rapid growth. Although less common, it can happen to Habaneros, Scotch Bonnets, and other chili peppers too. The reason why it develops more frequently in Jalapeño peppers is because they have a higher water content compared to other peppers. The higher water content can lead to absorbing more moisture when it rains, causing the pepper pod to expand. It is this expansion which can cause the outer skin of the Jalapeño to crack.