Capsaicin

Jalapeno peppers contain capsaicin, a chemical antioxidant that gives them the heat. If handled in a concentrated form, capsaicin can burn or even blister skin. Because capsaicin is an oil, it reacts poorly with water, but binds well with the fat in dairy products or certain acids like vinegar. That's why eating jalapenos with sour cream or cheese can cut the heat. Pickling jalapenos with vinegar can also reduce the heat.

Pickled Jalapenos

When pickled, jalapenos typically contain less heat not only because of the acidity of the pickling solution, but also because of how they are prepared. Peppers contain most of their heat-producing capsaicin in the seeds and white ribbing surrounding the seeds. Removing the seeds and ribs before pickling cuts the heat. Peeling the peppers before brining them in the pickling solution may also reduce the spiciness. Mix fresh hot jalapeno peppers with larger sweeter bell peppers together in one batch of pickles for an even milder flavor.

Fresh Jalapenos

Naturally hot fresh jalapenos make naturally hot pickled peppers. Choose milder jalapenos when fresh to reduce the heat when pickled. Typically, larger peppers have a milder flavor. Remove the seeds and ribs from this type of pepper to make jalapeno poppers or grill and stuff with cheese or sour cream to cut the heat even more. Top with bread crumbs and serve with a fresh lime margarita.

Warnings

Because the capsaicin in jalapenos can actually burn the skin, always wear rubber gloves when handling fresh peppers. Pickled jalapenos made from hot peppers may have the same effect, so handle carefully until determining the heat level. Remove gloves and wash hands before touching your face or eyes. Wash jalapeno residue and oils from knives and cutting boards before reusing the items. Avoid cutting into the seeds, which can release a large amount of capsaicin into the air or onto the rest of the pepper's flesh and create even more heat.