
This week we turned our attention to some happy, good-for-you microbes!
We began with reviewing the concepts of germs from last week by cutting out and assembling this “You Might be a Germ If…” book. It gave my preschooler some cutting practice and my kindergartener some reading practice. It’s a short little mini-book that you can use to review some of the negative aspects of germs. Feel free to click the page to download a copy if you think you’d like to try it out with your kids.

We then switched gears to start discussing the properties of yeast. Yeast is an amazing little micro-organism that can live with or without oxygen. Today we use it in baking, cosmetics, and other areas of every day life. Even though we can’t really see yeast cells because they are so tiny, in science we can watch their growth through chemical reactions.
Using a science experiment from Bill Nye, take 4 water bottles and label each (yeast-warm water, yeast and sugar-warm water, yeast-cold water, yeast and sugar-cold water). Fill the bottles accordingly, place a balloon around the outer lip of each bottle, and place in a conducive spot. We kept our two warm bottles in the living room and the two cold ones in the refrigerator.

Beware, your husband may ask you about what’s in the fridge. I know my husband loves living in our house. I’m sure it gives him a plethora of conversation starters for work. Ha ha ha.
Check the experiments after 12 hours and again after 24 and you will be able to observe a chemical reaction taking place.

The balloon of the warm yeast and sugar water mixture will be filled with a mixture of carbon dioxide and ethanol. This reactions is what happens when conditions are just right to multiply.
As an extension, we decided to see how yeast works in our kitchen. We used a 30 Minute Pretzel recipe to smell yeast, taste it in the dough, and observe how our pretzel designs “puffed” as they rose right before baking.

While the pretzels cooked, it gave us some time to write a little. My daughters each wrote a recipe for their grandma to use (with my youngest dictating to me). Although neither seem to include the “real” recipe, it gave a chance for some non-fiction writing with a little organization. Feel free to click the image below to download if you think it’s something you could use with your own kids.


We took a little time with a little “J” Sound Sort, in which we sorted words between those that started with a J and those that started with a G. How confusing can the English language get having two different letters that make the same sound? Geesh! The activity was a hit because we have “J” sound names in our family. Outside of that it gave us a chance to talk about the different words, just for the exposure. If you think you could use this at home, feel free to download by clicking on the image.
One of our favorite activities of the week was blow-painting our own germs. I found this idea on Pinterest from Raising Sparks and think it’s adorable. This is really not scientific, but it was a lot of fun and allowed us to discuss how we shouldn’t share straws or blow in people’s faces. Not only that, but we had some wildly creative stories that stemmed from the pictures!

Finally, our germy apples from last week. I was a little disappointed that our apples didn’t brown more (thanks a lot Granny Smith), but as soon as the kids touched them, they exclaimed over how squishy the cut apples were. I love how doing this experiment can be connected to how our own human skin protects our bodies from germs and microbes breaking through.

Please don’t forget to head on over to The Usual Mayhem and STEMmom to see what they’ve been working on this week. And, if you’re interested in a variety of Montessori ideas for germs, please visit Every Star is Different, who shared with her current germ unit with me. You will find lots of fun ideas to add to your own studies!
*Oh yeah, want to know what the results were of our petri dishes? I am so glad we checked them throughout the week because we had a few microbes growing in several dishes, but the home computer petri was really icky! The computer got a nice cleaning. Unfortunately, I had an epic fail at the final results because I preheated my oven where I was storing the petri dishes…and totally forgot to remove the tray. I would like to say the brownies that I made were worth it, but I doubled the batch and doubled everything but the sugar. So I didn’t even lose the petri dishes for a good treat in return. {Sigh…}

They look a little melted, huh? So sad…We’ll have to give it another try. Be sure to check out the Kitchen Pantry Scientist to see some “real” results.
Click the button below to be brought back to the introductory post for this unit. We have one more Tuesday to go before we share our free planning resources. Enjoy!
Linking to:







