Mad Science: Cranberry Chemistry and Architecture

Once again, in today's Mad Science we had two experiments. The first one focused on chemical reactions, and the second was a hands-on skill builder to practice spatial relations and exercise motor skills. I should note, I did not plan this program on my own. My partner youth librarian Sara is out with an unexpected illness this week, and I have been taking over her programs. She planned this and left me all the materials, so this morning my only job was to read up on the scientific concepts and carry out the program. We did cranberry-theme experiments today, to be festive and Thanksgiving-y.

Here is experiment one: Cranberry Chemistry.

Materials needed:

• Cranberry juice (unsweetened or no sugar added)
• Lemon juice
• Baking soda
• Clear plastic cups

The lesson for this experiment is to learn about the chemical reactions between acids and bases. It helps to have the visual aid of a pH scale on the wall, and talk to the kids about acidic, basic, and neutral liquids. It also helps to label where the liquids you'll be working with fall on the scale. I labeled where baking soda (9, very basic) and lemon juice (2, very acidic) are. I drew one on the white board, based off this picture:

First, we poured some cranberry juice into our cups and noticed that it is a dark red color. We talked about the fact that cranberries are an acid because they contain anthocyanins. We repeated that word a whole bunch, because it's long and hard to pronounce. I also wrote it on the board so they could sound it out if they were visual learners.

ANTHOCYANINS!

Anthocyanins are pigments that change color depending on whether they are reacting with an acid or a base. Cranberries, and therefore cranberry juice, naturally contain anthocyanins. 

After the cranberry juice was poured, we added a small amout of our base: baking soda. The juice is supposed to turn bright blue; we got as far as a half-hearted purple color. So technically the experiment worked, and it worked well enough to prove the scientific fact of anthocyanins true, but it was not the exciting and vibrant color I had hoped for.

The next step was to add another acid, lemon juice, back to the solution and watch it turn back to it's original red. This also pretty much worked. We did end up with cups full of red liquid again, and were able to discuss how the ANTHOCYANINS reacted with the acid in the lemon juice. 

Here is experiment two: Cranberry Architecture.

Materials needed:

• Fresh cranberries
• Toothpicks

The lesson for this experiment was mostly just to have fun. I demonstrated making a simple cube with the cranberries and toothpicks, then invited the kids to make one too. After they all mastered the cube, I gave them about 10 minutes to make whatever they wanted. 

Source: Little Bins for Little Hands

Then, I issued the kids a challenge: build the highest structure you can that will support the weight of a jumbo marshmallow. I gave them 10 more minutes to alter their creative structure, or tear it down and start something brand new. Then, after everyone was done, I balanced a marshmallow on the highest point of each one. Here is our winner with her giant cranberry tower! If you look closely, you can see that there are actually TWO marshmallows nestled in between the toothpicks. (I did get permission from her guardian for the picture to be posted).

I liked the cranberry architecture because it helps kids of all ages and developmental stages enhance their fine motor skills, motor planning, and spacial relations. It also helps them gain patience with manual projects and maximizes finger dexterity, which will come in handy for crafting, playing musical instruments, and typing. 

Here is the hand out that I sent home with each child, telling them about the experiments we did in case they want to recreate them at home. Click the image for a closer view.

Mad Science is a challenging program for me to host. I have never been very science-minded, so all my scientific information comes from Google and all my ideas for this program come from Pinterest. However, I had a great time working with these kids doing the cranberry experiments today. Programs like this, with more structure and smaller groups of participants, are great because you get more one-on-one time with the patrons. It's more like being a classroom teacher. I've said it before, but that's one big reason why I love being a librarian: you get the best of all educational worlds!