Jalapeño varieties vary in size and heat. Typically, a grower passes through a jalapeño field many times, picking the unripe, green jalapeños for market. At the end of the growing season, jalapeños naturally ripen and turn bright red. In Mexico and the United States, there is a market for ripe red jalapeños. They are kept on the bush as long as possible. When they are deep red and have lost much of their moisture, they are picked to be made into chipotles.