If carrots have lost their crunch, simply put them in a bowl of iced water along with a slice of raw potato. You could also fill a long plastic container with water and place the container into the refrigerator. After a few hours, check the carrots. If they are firm enough, take them out of the water, otherwise, leave them in longer, sometimes overnight.
When the carrots are rehydrated, dry them off and store them in a plastic bag in the refrigerator.
This works not only on carrots but also on celery and even heads of lettuce.
