In an experiment, I cooked a 12 organic chicken eggs from the same batch:
A) 6 in boiling water and
B) 6 in a pressure cooker:
- 6 eggs in a basket which is on a tripod inside the cooker
- 5 minutes in hot steam at 117 °C
- waited 5 minutes to cool down until the pressure was at room level
- alternatively I cooled the cooker with cold water from outside until the pressure was gone.
In both experiments the eggs were put in the cold cooker without a hole in the shell. The eggs were put in a bowl with cold water in the end.
I found that the shell and membrane of the pressure-cooked eggs were a lot easier to remove. (The eggs also seemed to taste fresher and more intense.) I could not find a reason or explanation. I have repeated this since 2016 once a week.
The effect is remarkable, because organic eggs are often much more difficult to peel than factory farming eggs.
Is there an explanation for the pressure-cooked eggs being easier to peel?
I would like to see reliable sources (e.g. papers or other trustworthy publications), not just personal opinions.