Peanut Butter Science

I used to give a program at the library called Peanut Butter Science.  Today someone on FaceBook asked me how to make homemade peanut butter and I was reminded of this program.
You could use this in a homeschooling session, or simply with your family for fun:

•  It seems to me that we first did some experiments with unsalted peanuts in the shell, then unshelled them and compared raw and cooked ones. (yes, I had bought both kinds from a nut company near where I lived.)

  
  I let them each take some raw ones home to grow (many reported back to me about them.
  Then we skinned the shelled peanuts and tossed the peanutsinto the blender. It usually was about a third full. I would begin blending. I like to use the burst mode. I think it gives me more control and I can pull the spatula out before it burst again. If it seemed a little dry, I would add vegetable oil to make a smooth mix and keep grinding until I thought it was blended. Can't remember if I added salt or not.
• Also, as part of the program, I had a tasting contest. I bought traditional jars (all smooth) like Skippy and Jiff. Plus various brands of supposedly 'natural' / organic'/ etc. and a dish of the peanut butter I just made.

  
  

  I had a huge box of plastic spoons. The children lined up and tasted each kind, throwing their spoon away after each taste so no saliva contaminated the jars. Then they filled out a form, voting for the one they thought was best. I'd put the score up on the white board. Fun.

  
  Naturally, I don't need 6 open peanut butter jars at home , so I had them put their names in a container and pulled out names. The first person could take home his or her choice. The second chose among the remaining jars, and so on until all the jars were taken. Fun.