Boiling water

Eigenvector said:

Seems like a simple enough subject. I had an interesting encounter
today while boiling water for my hot dogs (Hebrew National knockwurst
with more gristle than I care for). Pot was sitting on the burner,
bubbling slightly as the air in the water slowly comes out. The water
was just at the point when it begins to boil on the bottom, when it was
weird, all of the sudden the water erupts into a vigorous boil and stays
there. I've never seen anything like it before. One minute placid air
bubbles, next vigorous boiling. I know water can get superheated past
the boiling point in a microwave - but on an electric stove?

You know sometimes how when you watch paint dry, it's really boring?

Serene

Serene-y the Meanie said:

Eigenvector said:

Seems like a simple enough subject. I had an interesting encounter
today while boiling water for my hot dogs (Hebrew National knockwurst
with more gristle than I care for). Pot was sitting on the burner,
bubbling slightly as the air in the water slowly comes out. The water
was just at the point when it begins to boil on the bottom, when it
was weird, all of the sudden the water erupts into a vigorous boil and
stays there. I've never seen anything like it before. One minute
placid air bubbles, next vigorous boiling. I know water can get
superheated past the boiling point in a microwave - but on an electric
stove?

You know sometimes how when you watch paint dry, it's really boring?

My partner says I'm a big meanie -- which I knew -- and that water
can be superheated on an electric stove. ;-)

Serene

Eigenvector said:

Seems like a simple enough subject. I had an interesting encounter today
while boiling water for my hot dogs (Hebrew National knockwurst with more
gristle than I care for). Pot was sitting on the burner, bubbling
slightly as the air in the water slowly comes out. The water was just at
the point when it begins to boil on the bottom, when it was weird, all of
the sudden the water erupts into a vigorous boil and stays there. I've
never seen anything like it before. One minute placid air bubbles, next
vigorous boiling. I know water can get superheated past the boiling point
in a microwave - but on an electric stove?

I don't know how sudden you are talking, but I've never really seen it in
water in a pot on a stove. It happens quickly, but not instantaneously.

I'd like to correct a misperception you have about the air coming out of the
water. That's not air, it's steam. And it seems to start at random places on
the bottom. It will of course start on the bottom because that's where the
heat is coming from. These are called nucleation sites. Eventually the water
gets hot enough for most of the water on the bottom to start bubbling (rapid
boiling).

If you have a container with an excecptionally smooth surface (like glass),
there are fewer nucleation sites. This can make it more possible to
superheat the water and get that reaction one can see in a microwave.

I found out the hard way what happens when you suddenly increase the number
of nucleation sites. I poured orzo (rice shaped pasta) into a pot of mildly
boiling stock. Immediately the stock went into violent boiling and
overflowed the pot. What a mess. After that experience, I always turn the
burner down, add the orzo, then bring the heat back up a bit.

A very similar thing to boiling occurs in glasses of carbonated beverages
(beer, champagne, soda). There are nucleation points there too where the
trail of bubbles start. In that case, it is often dust or other particles on
the inside of the glass that cause the carbon dioxide to leave the liquid
and coalesce.

--
wff_ng_7 (at) verizon (dot) net

Eigenvector said:

Seems like a simple enough subject. I had an interesting encounter today
while boiling water for my hot dogs (Hebrew National knockwurst with more
gristle than I care for). Pot was sitting on the burner, bubbling slightly
as the air in the water slowly comes out. The water was just at the point
when it begins to boil on the bottom, when it was weird, all of the sudden
the water erupts into a vigorous boil and stays there. I've never seen
anything like it before. One minute placid air bubbles, next vigorous
boiling. I know water can get superheated past the boiling point in a
microwave - but on an electric stove?

I'd ask your doctor about a CT scan. Watching water come to
boiling temps can cause seizures and blackouts in people with
epilepsy.

-sw

In article <[email hidden]>,

Eigenvector said:

Seems like a simple enough subject. I had an interesting encounter today
while boiling water for my hot dogs (Hebrew National knockwurst with more
gristle than I care for). Pot was sitting on the burner, bubbling slightly
as the air in the water slowly comes out. The water was just at the point
when it begins to boil on the bottom, when it was weird, all of the sudden
the water erupts into a vigorous boil and stays there. I've never seen
anything like it before. One minute placid air bubbles, next vigorous
boiling. I know water can get superheated past the boiling point in a
microwave - but on an electric stove?

.. ::whistles the Twilight Zone theme::

Perhaps they released salt into the water and that brought it to a
faster boil.

Eigenvector said:

Seems like a simple enough subject.  I had an interesting encounter today
while boiling water for my hot dogs (Hebrew National knockwurst with more
gristle than I care for).  Pot was sitting on the burner, bubbling slightly
as the air in the water slowly comes out.  The water was just at the point
when it begins to boil on the bottom, when it was weird, all of the sudden
the water erupts into a vigorous boil and stays there.  I've never seen
anything like it before.  One minute placid air bubbles, next vigorous
boiling.  I know water can get superheated past the boiling point in a
microwave - but on an electric stove?

Water can be superheated on a stove top too... your water was too
clean so it could not nucleate at normal boiling point... you're
supposed to start tube steak in cold water anyway, and that would have
prevented the sudden and violent nucleation.

Emma Thackery said:

Perhaps they released salt into the water and that brought it to a
faster boil.

Nonsense.

"The Effect of Sugar and Salt"

"When salt, sugar, or any other nonvolatile compounds are dissolved in
water, the freezing point of the resulting solution is lowered and
it's boiling point raised. We take advantage of this effect by using
rock salt to melt ice on roads, and to freeze ice cream. As far back
as the 18th century, solutions of calcium chloride were used to reach
temperatures of -27? F. (-33? C.). The helpfullness of solutes at the
other end of the scale is, however, more limited. It takes one ounce
of salt to raise the boiling point of a quart of water by a mere 1?
F. A Denverite who wanted to boil water at 212? F. would have to add
more than half a pound of salt to that quart of liquid." [Berk, Z.
Braverman's Introduction to the Biochemistry of Foods, Amersterdam and
New York: Elsevier, 1976]
---

In fact adding some salt to the water would likely have prevented the
super heating as the salt would have given a point from which to begin
nucleation.

Sheldon

Sheldon said:

As far back
as the 18th century, solutions of calcium chloride were used to reach
temperatures of -27? F. (-33? C.).

At first, I thought you were asking, but I figured out that your
question mark (?) should have been a degree symbol (°). It's too early
for me, today. LOL

--
Zilbandy

Zilbandy said:

Sheldon said:

As far back
as the 18th century, solutions of calcium chloride were used to reach
temperatures of -27? F. (-33? C.).

At first, I thought you were asking, but I figured out that your
question mark (?) should have been a degree symbol (°). It's too early
for me, today. LOL

Google doesn't seem to be able to decipher certain symbols so instead
interprets those as a question mark.... Google isn't working at all
right now, they are doing roadwork.

"Sheldon" <[email hidden]> wrote in message
news:[email hidden]...

Eigenvector said:

Seems like a simple enough subject. �I had an interesting encounter today
while boiling water for my hot dogs (Hebrew National knockwurst with more
gristle than I care for). �Pot was sitting on the burner, bubbling
slightly
as the air in the water slowly comes out. �The water was just at the point
when it begins to boil on the bottom, when it was weird, all of the sudden
the water erupts into a vigorous boil and stays there. �I've never seen
anything like it before. �One minute placid air bubbles, next vigorous
boiling. �I know water can get superheated past the boiling point in a
microwave - but on an electric stove?

Quoted message said:

Water can be superheated on a stove top too... your water was too
clean so it could not nucleate at normal boiling point... you're
supposed to start tube steak in cold water anyway, and that would have
prevented the sudden and violent nucleation.

I'll have to mention to the city that the water was too clean - I'm sure
they'll do something about that pronto!

Sheldon said:

Google doesn't seem to be able to decipher certain symbols so instead
interprets those as a question mark.... Google isn't working at all
right now, they are doing roadwork.

Ahhh, I didn't know that about Google. I've never used it for posting
to Usenet. Sorry for the confusion. 🙂

--
Zilbandy