Final answer:
Egg whites should be whipped in a metal bowl as it conducts heat well and provides stability. Plastic bowls should be avoided as they can absorb oils and fats. Glass bowls can be used, but they are not as ideal as metal bowls. Copper bowls are not commonly used.
Step-by-step explanation:
Egg whites should be whipped in a metal bowl.
When egg whites are whipped, air is incorporated into the mixture, which causes it to increase in volume. A metal bowl conducts heat well, which helps to stabilize the whipped egg whites. This is important because egg whites are temperature sensitive, and a metal bowl can help to prevent over-whipping or under-whipping.
Using a plastic bowl is not recommended for whipping egg whites because plastic can absorb oils and fats, which can interfere with the whipping process. Additionally, plastic is not as good at conducting heat and can result in unstable whipped egg whites.
A glass bowl can be used to whip egg whites, but it is not as ideal as a metal bowl. Glass is a poor conductor of heat and may not provide the same level of stability as a metal bowl. However, it is still a better option than plastic.
Using a copper bowl to whip egg whites is not common, but it can be done. Copper is an excellent conductor of heat and has an effect on the stability and texture of whipped egg whites. However, it requires special care and maintenance as copper can react with some substances, so it is not the most practical choice for most home cooks.