Aunt Gladys / Chemistry Yo, Dude! (That\'s

Aunt Gladys / Chemistry

Yo, Dude! (That's how we would say "Howdy, Aunt Gladys!" here at college.)

Thanks for your letter and the $2.00 you sent with it. Probably this weekend I will go out and buy myself something nice, like you suggested.

I am glad you and Uncle Wilbur are well. Everything is good here at school. I am pretty busy and I am learning a lot. Especially chemistry.

I'm happy to be able to answer your question for you. You asked how come the tin foil melted overnight on your meatloaf. Don't worry, nothing is wrong with your refrigerator and you and Uncle Wilbur will not have to get a new one. And no, it wasn't because you snuck some ground turkey in there because the doctor told Uncle Wilbur he needs to start watching his cholesterol. It's actually because of the ketchup. Now, don't go writing a letter to the Ketchup Advisory Board because there isn't anything they can do. Plus I don't think there really is a Ketchup Advisory Board. Mr. Keillor might just have made that up for that radio show.

Anyway, here's the story: As you know, ketchup is made from tomatoes. Tomatoes taste good because they have a combination of sugars and acids. The sugars, mostly fructose and glucose, make the tomato taste kind of sweet. The acids, mostly citric and malic acids, make the tomatoes kind of tart (University of Illinois Extension, 2007). You don't have to worry about these kinds of acids. They are not like the acid in Uncle Wilbur's truck battery. These acids are actually in a lot of fruits and vegetables and they are good for you.

The acids aren't very good for tin foil, though. The tin foil has a metal in it called aluminum. The acid reacts with the aluminum and makes little holes in the foil. Then you get that gray stuff on the top of the food. It's called a chemical reaction. Believe it or not, it actually makes aluminum salt, which looks like white spots on the food. It is safe to eat but looks gross. You probably should pick it off before serving the meatloaf to Uncle Wilbur or else he could totally freak out. There is nothing wrong with the meatloaf after you pick off the gray stuff and the white spots (Callaway, 2012).