I'm not sure how my son stumbled onto this trick, but it is definitely science related.
Eggs that are difficult to peel have low PH values are are therefore acidic. As eggs age, they loose carbon dioxide and becomes less acidic and thus easier to peel. Some eggs are coated with oil during the cleaning process which inhibits the escape of the carbon dioxide making them difficult to peel.
7-10 days after the egg has been laid is the optimal time to peel it. Adding a spoon full of baking soda to the cooking water will raise the PH value making the eggs easier to peel.
For this egg blowing method to work the eggs needed to have higher PH values. The eggs we buy are delivered weekly to our house on the egg truck. They are fresh and not coated with oil so almost all of them are easy to peel.
This post is linked to:
Real Family Fun
Tot School Tuesday