My DTS outreach team was being welcomed into the YWAM Davao base and they had us try some Philipino delicacies. Balut and Durian! Balut is a cooked fertilized duck egg. It can be anywhere from 17 to 21 days old. The older they are the more recognizable the bird inside becomes and the harder it is to swallow and stomach it. All of ours where at different ages and stages so you'll see some peoples were a bit older than others.