My chickens are still young (they hatched last November), so they are barely laying medium sized eggs. 23 days ago I had one go broody, so after some research I grabbed 12 eggs from the fridge let them sit out for a day and then put them under her. After some issues (neighbors kids, neighbor's roo coming for a 'visit' and scaring her off the nest . . .) we had 9 eggs left. So yesterday was hatch day, this morning 8 of the 9 have hatched and the last has pipped, though not well - we'll see if it makes it. So, all said 8 of 9 medium eggs that had been refrigerated between 11 and 12 days, under my broody, hatched to healthy peepersy!