Fresh jalapeño peppers can be stored in a plastic bag in the vegetable crisper of a refrigerator. The peppers should be sliced or chopped and placed in a heavy-duty freezer bag or airtight container for freezing.
In the refrigerator, fresh jalapeños will keep for about a week. In the freezer, they stay fresh for 10 to 12 months. Jalapeños are native to Mexico and contain capsaicin. Capsaicin gives the peppers their spice and contains antibacterial and anticarcinogenic properties. The peppers also provide antidiabetic and analgesic effects. Jalapeños are also a significant source of vitamin C, which helps boost the immune system.