“the null hypothesis for a boiling water test would be that a copper disc or clad vessel would bring water to a boil faster.”
To put us on the same page, the null hypothesis always start with the two things/conditions have no real difference or no real relationship, and it is up to the experiment to reject the null hypothesis and establish a statistical difference. In other words, the default position is nothing, and let the data show otherwise.
“In inferential statistics, the term “null hypothesis” usually refers to a general statement or default position that there is no relationship between two measured phenomena, or no association among groups.”
In the pure sense, what Franz really showed isn’t that “copper and aluminum pots are the same”, rather that he couldn’t establish a statistical difference. His data were not strong enough to disprove his null hypothesis (two pots being same).
For a typical burner or inductor and several gallons of water heated from room temperature, neither 1. a pan’s thickness nor 2. whether it is cladded or disk based,nor 3. whether it’s copper, aluminum, steel, or cast iron will make more than a very small difference in the time to boiling.
This is false. Watt-for-watt, disk-based, CI, and clad pans will reach a boil more slowly than will aluminum and copper. In my tests with the new Panasonic KY-MK3500 Met-All hob, the time-to-boil differences for 4L with 2400 watt output were substantial.
Thanks Kaleo, that’s interesting about the Panasonic hob. I remember I did get different results from CenturyLife with the disc based cookware that I tested. When I timed the Cuisinart Professional disc base 4.5 l pot (disc base right to the edge like Demeyere Atlantis, but aluminum core) to boil, it was actually 2 minutes slower than my old MulticCad Pro. On the other hand, the Denmark Tools for Cooks disc base 4.5 l (again full disc to the edge) was tied for speed with my old MultiClad Pro. The Denmark Cooks pot seemed lighter and thinner than the Cuisinart Professional pot (I weighed all the pots I tested but didn’t have a caliper/micrometer to verify thickness).
Which is why all my testing left me feeling like thickness had more impact on cooking speed, all else being equal. Copper and aluminum pots are customarily more thinly made (e.g. 2.5mm) materials than most s/s clad or disc bottom pots. I wanted, but didn’t get a chance, to test a disc bottom Thermalloy 4.5 liter pot (which had a 6 mm thick bottom) to see if there was any difference.
A joke. Since you asked why does anyone care about copper vs aluminum vs cladded cookware… I made an analogy that why does anyone care about you cook on induction.
I have a hot plate from when we were redoing a kitchen. But my kitchens have this equivalent. And I wouldn’t trade it for the most expensive gas or electric even if given a $1k on top of that.
