Why is it necessary to reduce the wine before

adding the stock? Doesn’t all the alcohol burn off
anyway during the long simmering period? Actually,
no.
Despite the fact that alcohol has a lower boiling
point than water (173°F versus 212°F), it’s nearly
impossible to burn off all the alcohol from a pot on a
burner. This is because when alcohol and water are
mixed, the alcohol actually lowers the boiling point of
the water. Water molecules are like tiny magnets.
Each one has two legs that are attracted to the heads
of the other molecules. Stacked up like a human
pyramid, they form a semi-rigid pattern that’s fairly
difficult to escape. Add some molecules of ethanol
(alcohol) to the mix, and things become a little
shakier (have you ever tried building a human
pyramid while drunk?). The molecules of ethanol get
in the way of the water molecules, so their bonds are
not quite as secure. This makes it much easier for
individual molecules of water to escape the surface
of the liquid and evaporate.
Bring a pot of liquid with a 5-percent alcohol
content to a boil, and the vapor being released is
actually over more than 60 percent water. Reduce
that alcohol content to 2 percent, and the vapor
released becomes closer to 90 percent water. The
closer you get to removing all the alcohol from a
solution, the harder and harder it becomes to