A carton of firm, pale tomatoes from the farmers market need not wait weeks on the counter. Stick the unripe fruit, stem end up, in a paper bag with a few holes punched in it, then fold the top over and let it sit. According to the University of Illinois Extension, the punctured bag traps the tomato's own ethylene gas close to the fruit and, depending on how green it was to begin with, can lead to full ripeness in just one to five days.
The real reason tomatoes keep ripening after harvest
