Why do some recipes call for adding eggshells or membranes in a clarification process for stock (as part of the consomme raft), and does it actually help clarify?

Question

Eggshells in your stock? Find out the purpose behind this unusual ingredient in a consommé raft and whether it really helps with clarification.

Answer 1

Eggshells and membranes are added to a consommé raft because they act as binding agents, attracting impurities and solidifying during the simmering process, which significantly aids in clarifying the stock. Yes, it does help clarify.

Detailed Explanation:

The clarification process for consommé relies on creating a 'raft' that floats on top of the simmering stock. This raft is typically made from ground meat, aromatics (like carrots, celery, and onions), egg whites, and importantly, eggshells and their membranes. Here's how each component contributes to the clarification:

1. Egg Whites: The primary clarifying agent. As the stock heats, the egg whites coagulate (solidify), trapping suspended particles and impurities within their protein structure.

2. Ground Meat: Adds flavor and also contributes proteins that help in the coagulation process, further trapping impurities.

3. Aromatics: Provide flavor to the consommé and also contribute some solids that aid in the raft formation.

4. Eggshells and Membranes: This is where the magic happens. The calcium carbonate in the eggshells helps to further coagulate the proteins in the egg whites and meat, creating a stronger and more effective raft. The membranes, being fibrous, act like a net, helping to trap even finer particles that might otherwise escape. They also provide additional surface area for impurities to adhere to.

As the stock simmers gently, the raft slowly cooks and solidifies, drawing all the cloudiness and unwanted particles to itself. Once the consommé is finished, the raft is carefully removed, leaving behind a perfectly clear and flavorful broth.

Pro Tip:

Don't stir the consommé once the raft has formed! Agitating the liquid will break up the raft and release the trapped impurities back into the stock, defeating the purpose of the clarification process. Maintain a very gentle simmer to keep the raft intact.