While freshly picked jalapeno peppers only last around one week before spoiling, an unopened jar of them can last several years. The reason that jalapenos in a jar last so long is that they go through the canning process, which helps to preserve them. This process involves heat pasteurization and the addition of ingredients used to prevent the growth of harmful spoilage microorganisms.
Storing Your Potent Peppers
Jalapenos, a type of chili pepper, are high in capsaicin, the ingredient that makes them so hot. Unfortunately, capsaicin doesn't help to preserve the peppers and like any vegetable, they have a limited shelf life unless they are canned, dried or frozen. Commercially canned jalapenos in a jar usually have the longest shelf life of all, lasting from two to five years when left unopened in a cool, dark cabinet. Canned jalapenos last the longest when stored between 32 and 41.
Once You Open the Jar
While you can store your unopened jar of jalapenos in your pantry, once you've opened it, you need to refrigerate it at temperatures less than 40 F within two hours to prevent the growth of spoilage microorganisms. An opened jar of jalapenos will last up to two months in the refrigerator. You can also freeze your jar of jalapenos for up to six months at 0 F and thaw them prior to use. Note that freezing the canned peppers may give them a bit of a mushy texture. Formerly frozen peppers work best in cooked dishes, like soups or stews, rather than in fresh salsa or salads.
Canning Your Peck of Peppers at Home
Jalapeno peppers are a low-acid vegetable, which means that if you want to can them at home, you'll need to add acidic ingredients like vinegar or lemon juice to your canned peppers to help preserve them. Pickle your jalapeno peppers in a vinegar solution if you want to pasteurize them at low temperatures around 180 to 185 F in a water bath canner. For jalapenos that aren't pickled, you'll need to pack them in water with a bit of lemon juice before using a pressure canner to properly preserve them. Home-canned pickled jalapeno peppers that are stored between 50 and 70 F typically last between 12 and 18 months. Those that aren't pickled last between eight and 12 months, according to the University of Minnesota Extension.
Should I Eat These Peppers?
You'll need to visually inspect your peppers and the glass jar they are contained in to determine whether or not your jalapenos are still edible because spoiled peppers can make you very sick if you eat them. If you see visible mold inside the jar when you open it or the peppers have an unpleasant aroma, discard them because they've gone bad. Check your jar's lid to see if it's loose or bulging, both of which are signs that the seal of the jar is no longer intact and the jar's contents are spoiled. Cracks in the jar can also lead to spoilage of your peppers and you should discard cracked jars of jalapenos.