"William Graham" > wrote in message
news:za%kb.839222$uu5.148897@sccrnsc04...
>
> "Vox Humana" > wrote in message
> news
> >
> > "Brian Mailman" > wrote in message
> > ...
> > > Vox Humana wrote:
> > >
> > > > The easy way to make Dulce De Leche is to put an unopened can of
> > sweetened
> > > > condensed milk into a small pan. Add water to bring it to about 3/4
> the
> > way
> > > > up the can.
> > >
> > > That's an easy way to make an explosion.
> > >
> > > Add water to completely cover the can AT ALL TIMES by at least 2". Do
> > > not answer the phone while this is going on. Do not answer the door.
> > > Do not pass go, do not collect $200.
> > >
> > > Making this is safe, but it does need to be watched, do not allow the
> > > can to 'surface' in the water at any time.
> > >
> > > B/
> >
> > Why does covering the can make it safer?
> >
> >
> I don't think covering the can is necessary....But you don't want to run
out
> of water, so put the can in a large pot with lots of water, and watch it
so
> you don't forget it....If you run out of water it will explode....As long
as
> there's plenty of water, the contents of the can won't boil because they
are
> under slightly higher pressure, and the water in your pot won't go over
> boiling at normal atmospheric pressure, so it's safe.....

The reason then is to have more water as insurance against boiling the pan
dry. That makes sense, but is a different matter than "the can will explode
if it isn't fully submerged."