Boiling Water in a Stainless Steel Pot on a gas stove. Domestic kitchen, food preparation.
Food - Drink
The Optical Illusion Behind Salting Your Boiling Water
There is a misconception that salt makes water boil faster, but this theory comes from the optical illusion of bubbles appearing.
The bubbles aren't necessarily caused by water turning into vapor. Instead, like the spaces created by scratch marks, the salt creates new openings for bubbles to take shape.
In truth, given a large enough pot of water, salt would slow the process since its addition increases the boiling point.
Although it doesn't make water boil quicker, adding salt can be beneficial, such as improving the flavor of pasta.
The trick is to add salt after the water has reached its boiling point so it will dissolve and not just sink to the bottom.