Re: [Phys-L] popcorn physics

[brian whatcott <betwys1@sbcglobal.net>]

On 6/18/2013 9:09 PM, Anthony Lapinski wrote:
> /snip/
> I know that popcorn pops because the small amount of moisture in them gets
> superheated when it's under high pressure. I read somewhere that "ideal"
> popcorn kernels have a 14% moisture content. Does anyone know how this was
> figured out? How can the moisture content of a popcorn seed be measured?
/snip/

Sounds like a school lab.... place a popcorn grain sample in an 
enclosure with a beaker of water with a roll of blotting paper to 
provide a 99% humid atmosphere after a day or two.
Weigh.
Place the popcorn grains in an oven ramped to  95 deg C and held for an 
hour or two....
Reweigh.
Draw a moisture content versus delta mass/mass ratio graph.

Then.... for a new sample, its present weight versus its dry weight 
leads to a moisture estimation.

I suspect that figure of 14% humidity is an estimate with rather wide 
error bands.
Suppose you tried stabilizing grains in  enclosures maintained at 11% 
and 17%.
How sure would you be of those humidity levels?

Brian Whatcott   Altus OK