sort of. Dissolved solids like salt and sugar will
in fact increase the boiling point of water,
causing it to come to a boil more slowly, but
the effect is minimal (the amounts normally
used in cooking effect less than a 1-degree
change). For it to make any significant
difference, you’d need to add it in really vast
quantities. So for the most part, you can
ignore this one.- A watched pot never boils. Definitely true.
Avert your eyes.
On Salt and NucleationSo, if salt doesn’t lower the boiling point of water,
how come throwing a handful of salt into a
simmering pot will cause a sudden eruption of
bubbles? It’s because of tiny things called nucleation
sites, which are, essentially, the birthplace of
bubbles. In order for bubbles of steam to form, there
has to be some sort of irregularity within the volume
of water—microscopic scratches on the inside
surface of the pot will do, as will tiny bits of dust or
the pores of a wooden spoon. A handful of salt
rapidly introduces thousands of nucleation sites,
making it very easy for bubbles to form and escape.
The same principle is used to “seed” clouds.
Releasing dusty particles from an airplane causes
millions of nucleation sites to be created in the moist
atmosphere so water vapor droplets can coalesce
and form clouds.