Mushrooms and Truffles Grown from spores, these delicious fungi with a meaty texture are also prized for being nutritional superstars with high levels of Vitamin D. How to store Mushrooms will last longer if kept cool and dry. Place in a paper bag in the produce drawer of the fridge and use within a week. How to prep. Mushrooms:Just before using, rinse under cool, running water and pat dry. Use a spoon to gently scrape out. Brush with olive oil and sprinkle with a pinch of salt. Grill for 3-4 minutes...