Re: [at-l] boil, boil...

[hopefl@juno.com]

When milk is pasteurized, it is only heated to 147F for about half an
hour.  I understand that heating water to 170F for two minutes will kill
any of the micro monsters. (Orange Bug, did I understand that correctly?)
Assuming that I was listening and all pathogens die after being exposed
to 170F for at least two minutes, then water heated til steam bubbles
form will be protected. 

A word of caution is needed here. Air is dissolved in water. When the
water is heated the air begins to come out of the water. This can happen
well below boiling or even 170F. So, it is important to understand that
bubbles forming around the sides of the pot are most likely air and not
steam. When the water temperature approaches boiling ( meaning a rolling
boil), bubbles will form at the bottom of the pot, right above the heat
source,  and immediately head for the surface. When the bubbles form in
mass, we have a rolling boil. 

Altitude is a consideration. As atmospheric pressure decreases, the
boiling point of water decreases. Along the AT this is not a concern
because the increase in altitude (and the resulting decrease in air
pressure) is not sufficient to lower the boiling point below 170F. In
fact, atmospheric pressure must be lower by 30 percent to also lower the
boiling point below 195F. And 195 is greater than 170. Better check me on
this one too Orange Bug. So, at around 10,000 feet water boils at 195F.
CDT and PCT hikers might want to  note this. 

If anybody cares, standard atmospheric pressure is 101.3 kPa at 0 degrees
C, that's sea level at the freezing point. Atmospheric pressure at 10k
feet is about 70 kPa or about 30 % less than at sea level. Water boils at
90C at 70 kPa. (in round numbers) If anybody cares.   Hopeful

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