Re: Why does boiling stock with egg whites and egg shell clarify it?

Hi! Fun question. I shared it with two colleagues. One said it is really only the egg white that counts, the other that only the shell that counts. I tend to lean towards both contributing, but our answer is a best understanding.

The egg white is being used as a clarification agent. The heating coagulates the egg white which traps various things [such as small particulate matter]. It probably also works partially as an anti-foaming agent.

The egg shell supplies calcium carbonate. This probably is a flocculant in its own right and also adjusts the pH.

So, without doing the experiments I would predict that the two together are better than either alone -- but it is a worthy experiment to perform.

Enjoy your soup. Cheers.