A long time ago, I read somewhere, that there is a very specific reason, why we put salt in the water for cooking pasta: The point is to hinder the water from absorbing flavor and nutrients from the pasta. With soup its the other way around: We want to absorb the flavors into the water, which is why we salt it only at the end.
The explanation was, that salt "ionizes" water, which somehow makes it less likely to absorb things.
Is there any truth to this theory?
Source:
https://www.finecooking.com/article/the-science-of-salt
Quote:
Because pure water draws salts and other soluble nutrients from the
interior of vegetables, salting vegetable cooking water also minimizes
nutrient loss.
Best Answer
As a chemist, I'd say that you have it all wrong.
You add salt to pasta water to have the salt infuse into the pasta. So as the dry pasta absorbs water, salt comes into the pasta too. Salted pasta tastes better than unsalted pasta.
Salted soup tastes better than unsalted soup. Salt enhances our perception of the flavors in the soup, but it does not extract the flavors.