 All right, welcome back to Kids Fun Science. My name's Ken. Today's experiment is how to tell if an egg is bad. What you need for this experiment is a cup or a bowl, water, eggs, and a spoon. So how many times have you cracked an egg in a bowl only to question yourself whether the egg has gone bad or not? Unfortunately, eggs aren't the easiest to determine the freshness as the shell kind of hides all the condition. But I have a way to be able to show you scientifically how we see it if it's fresh or bad. Simply fill a cup full of cold tap water, place your eggs in it. If they sink to the bottom, then they're fresh and they're good to eat. A bad egg will float because the large air cells that form in that space will make it float. Any floating egg should be thrown away. So as you continue to test here, I've seen two good eggs, I'm going to continue to go through. I've got the third egg here, put it in, and we've got a bad egg. It's floating, so it's got those air cells inside the egg and therefore making it float, so I want to throw that one away. So a carton's trays are sold in the USA are sell by sell by dates. And the first ignore the sell by date, the USDA mandates that any sell by date on eggs be 21 to 30 days when they were packed. Sell by date is very general and while it's very helpful for grocery stores, it's not very useful for cooking at home. There's a more reliable way to figure out whether your eggs are good or bad from the carton, the side of the carton. There's a long numeric code listed on or below the expiration sell by date. The last three digits of the longer code corresponds with the Julian date, which counts for each day of the year of the number between 1 and 365. For example, 140 is May 20th. So the USDA has a handy chart, which I have the link in my description in case you don't want to look up the math every time you can look at their chart. I hope you enjoyed this experiment. If you did, remember to click thumbs up and to subscribe. And thanks for watching. Well, another bad egg.