Friday, October 29, 2010

Does adding salt to water make it boil faster?

Nope, not a bit.  In fact, adding salt raises the boiling point of water, so it will take slightly longer to boil, on the order of a couple milliseconds.  This has a lot to do with thermodynamics (enthalpy, entropy, specific heat capacity, partial differential equations, etc.) but I won't bore you with the details.  Salt will flavor whatever you're boiling, but it won't decrease the time it takes to boil.     


  1. Wouldn't this mean that the cooking time would be decreased slightly because of the increased temperature of the water?

  2. Science Lady here - yes, the cooking time would decrease very slightly when you add salt. Altitude (pressure) has a bigger impact on water boiling temperature and hence cooking time. When we camp up at 10,000-12,000 feet in the mountains, it can take a very, very long time to cook pasta or rice because water boils at approximately 190 F, as opposed to 212 F at sea level.