Answer:

When meat is boiled, high temperatures cause proteins to coagulate, forming a layer of foam. This foam is not harmful; in fact, it can add a sweet and rich flavor, making its use in soups or for boiling vegetables quite normal. The amount of foam produced depends on the protein content in the specific type of bone and meat.

However, this layer of foam often contains impurities such as dust, sand, or residual hair, which can make the broth cloudy, unappetizing, and less hygienic. To enhance the appeal of dishes, cooks should select clean meat, prepare it thoroughly, and blanch it once in boiling water to remove these impurities.

During the main boiling process, add a few slices of ginger or purple shallots to enhance the broth's aroma. Continuously skim off any foam to ensure the broth remains clear and tastes clean. While blanching might lead to a slight loss of nutrients, it ensures a high-quality, hygienic broth suitable for preparing various soups, noodle dishes, or vermicelli.

Boiling meat from cold water for the first few minutes helps remove impurities. *Photo: Bui Thuy*

Associate Professor Doctor Nguyen Duy Thinh

Institute of Biotechnology and Food Technology, Hanoi University of Science and Technology