Do salt or vinegar in the boiling water help peeling eggs?
In another question, a user commented
I've heard some tales that vinegar helps with peeling afterwards
and another one responded
both are totally useless
That struck me as a very good question.
If salt and/or vinegar are added to the boiling water, does that help with the peelability of the boiled eggs? And if there is an effect, how noticeable is it, especially in comparison to other factors such as egg age?
Note that I am not asking about other methods for making eggs easier to peel. Nor is this about the use of vinegar in making poached eggs. I am asking specifically for confirmation or disproval of the salt/vinegar "tale", preferably founded by something more than just "I heard it too".
Best Answer
A chemist here.
I do add baking soda (Sodium bicarbonate). I am satisfied with it as I never got the white stuck to the shell since I do this. However I can't say that the same eggs would have done otherwise without baking soda.
A possibile reason is that the adhesion of the inner coagulated white to the calcium carbonate shell is modulated by pH. In other words rising the pH of the cooking water by a salt with alkaline hydrolysis - such as baking soda - mimicks the conditions of not extra fresh eggs.*
Note that adding table salt (Sodium chloride) cannot work this way as for the pH is let unchanged. I never tried as for I cannot think of an obvious mechansm for why It should work.**
Concerning adding vinegar (a solution of acetic acid in water): the common explaination is that the shell is softened by dissolution. This would also prevent the inner to shell adhesion as well make the shell itself prone to peel off.
I haven't tried this, neither.
*Eggs which are not very fresh undergo changes resulting in a higher pH and are easy to peel.
**The behaviour of proteins is affected by several parameters such as pH, temperature, ionic content. I cannot exclude that adding table salt is indeed effective.
Starting the cooking in already warm tough not necessarily boiling watet is reported effective too. Rationale is that a fast albume coagulation results in the white to inner shrink without setting on the the film near the shell. Worth a try...
Pictures about "Do salt or vinegar in the boiling water help peeling eggs?"
Quick Answer about "Do salt or vinegar in the boiling water help peeling eggs?"
Add salt and vinegar to the water before cooking. The salt permeates the shell a little bit, and the vinegar helps to break down the shells, making them easier to peel.Does vinegar and salt help peel eggs?
Add salt to the water to help keep the eggshells from cracking too soon. Add vinegar to water in the pot to make eggshells easier to peel.Does adding vinegar to boiling eggs make them easier to peel?
These two hacks were tested to see which of them actually work. Adding vinegar to boiling water made it easier to peel. Adding baking soda made it almost impossible to peel.Does salt make boiled eggs peel better?
The salt won't affect the flavor of your eggs; it helps solidify the proteins within the egg, helping create an easier to peel egg!How do you get boiled eggs to peel easily?
After boiling, let the eggs sit in the ice bath for at least 15 minutes, then peel them or refrigerate them (unpeeled) for up to seven days. To peel, gently tap the egg at the big end first, then the small end, then all around. I prefer not to roll them because it's easy to break the white.More answers regarding do salt or vinegar in the boiling water help peeling eggs?
Answer 2
Based on what I've read and understand, salt and/or vinegar don't have any effect on how easy an egg is to peel. The most determining factor is age. Here's why.
From Fresh Eggs Daily:
Just under the eggshell is a pair of thin whitish membranes. They help to keep air out of the egg. Once an egg is laid, an air pocket begins to form between the two membranes at the blunt end of the egg. This air sac will continue to grow as the egg ages. Part of the difficulty in peeling fresh hard-boiled eggs stems from the lack of space between the two membranes. Older eggs peel easily because the air between the membranes has begun to separate the egg contents from the shell.
(Picture from different source.)
Sources: Stack Exchange - This article follows the attribution requirements of Stack Exchange and is licensed under CC BY-SA 3.0.
Images: Mariana Montrazi, Monstera, Pixabay, Monstera