Science Fair: Exploring Moisture Loss When Cooking Potatoes

Three days before Christmas, I posted this to Facebook:

Many of my friends and family members had excellent theories as to why this was reasonable or why this had to be a typo. 

Then this happened:

Trevor was totally onboard. His teacher liked the idea, too. It officially became his science fair project. So he washed, sliced and weighed.

He roasted, boiled and fried. 

 Then he weighed again.

And then he did the calculations and made a powerpoint presentation. 

Fascinating! The roasted potatoes lost 41% of their weight during cooking. The boiled potatoes weighed 113% of their original weight after cooking.

And, since you're all dying to know, I roasted 15 lbs. of potatoes for 15 people (14 adults + Trevor) for Christmas and it was way too many with all the other dishes I served, even with the moisture loss. Now I know!