Final answer:
The addition of salt when poaching eggs primarily serves to enhance the flavor, rather than affecting the cooking time or texture. In high altitude areas, the lower boiling point of water extends cooking times, explaining why eggs cook more slowly in Denver than in New York City. For pasta, while salt can slightly raise the boiling point of water, the primary reason for its addition is flavor enhancement.
Step-by-step explanation:
The addition of salt when poaching eggs is typically done to enhance flavor, not to alter cooking time or improve texture significantly. While salt can raise the boiling point of water slightly due to colligative properties, the change is minimal and does not significantly affect cooking times at the scale of home cooking. Furthermore, in the context of poaching eggs, the primary goal is to delicately cook the eggs without reaching a rolling boil, which would disrupt the gentle cooking process. Instead, flavor enhancement is the main purpose behind adding salt to the poaching liquid.
When discussing how an egg cooks more slowly in boiling water in places like Denver compared to New York City, it's important to understand that the boiling point of water changes with altitude due to pressure differences. At higher altitudes, like in Denver, the pressure is lower, which means water boils at a lower temperature. Therefore, it takes longer for an egg to cook because the water is not as hot as it would be at sea level, like in New York City.
While additives can improve taste, texture, and appearance of foods, in the case of adding salt to water before cooking pasta, the primary effect is on flavor -- the slight increase in boiling temperature is typically not sufficient to make a notable difference in cooking speed.