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One of the books we’re using as part of our science curriculum this year is Science in the Kitchen by Rebecca Heddle (an Usborne book). It explains wonderful, easy experiments using items you have around the house!
Last week, we talked about taste buds and did some tests with sweet and bitter foods. Today, we discussed sour things and conducted a test with red cabbage water to see which foods and beverages are acids and which are bases. (The book calls them non-acids to keep it simple for younger learners.)
First, while I boiled water, the girls tore the red cabbage into small pieces and put it into a pot. When the water was boiling, I poured it over the cabbage pieces and let it sit until it cooled off (30-40 minutes). Then, I strained out the cabbage leaves. We were left with pretty purple cabbage water to use for our experiment!
Next, I filled lots of applesauce cups that were destined for the recycle bin with the red cabbage water.
Then, we created a list of foods and drinks we wanted to test. (We didn’t buy anything special—just looked around to see what we had!) The girls made predictions about whether they contained acids or not. We decided to check lemon juice, sugar, cinnamon applesauce, apple juice, milk, grape juice, apple cider vinegar, salt, filtered water, Coke Zero, and iced tea.
The red cabbage water turned pink when acids were added and stayed purple or changed to a dark bluish-green when bases were added. Some of the foods yielded obvious results immediately. With others, the “answer” became more obvious after it had sat there for a while.
I had the girls check their predictions against the actual results on the chart we made. They were only wrong three times!
We had quite an array of colors by the time we finished.
This experiment was a lot of fun, and the only cost was time and the money I spent on red cabbage!
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More kitchen chemistry resources:
– Amazing Kitchen Chemistry Projects You Can Build Yourself
– Janice VanCleave’s Chemistry for Every Kid: 101 Easy Experiments that Really Work
– Testing For Starch Experiment
Why does this do this? Why would the cabbage water be able to tell you if something had acid in it, why cabbage? And why would it change color? Why are some of them instant and some have to sit? I have a hard time with most experiment books because They do not explain the Why’s of how this worked and why it did this. Which seems like the most important part of doing the experiment, being able to explain this did this because of this. Or this did not do this because of this. As a homeschool parent that has a child that loves science 4th grade I have not done much with science because most of the experiments I find do not explain the why’s so that I will be able to explain it to her or answer of questions. I am starting to also homeschool my 8th grader that does not like science anymore probably for the same reason that you find that parents don’t like it because in school it was boring and overwhelming with stuff to memorize and not not know what it meant. I just found your site and am looking around , actually I am clicking through the Aug calendar wondering if that would be a great place for us to start. I looked at your candle / oxygen experiment and LOVED the paragraphs after the experiment explaining why it all happened , I was thinking I may have found what I have been looking for but then this one didn’t have that. Which may be a flaw in the book this experiment was in and in that case It would be another science book i wouldn’t want to buy. This ended up being very long. 🙂 I would love any how and why ‘s on this experiment so we could do it. And if you have any ideas for good books that do give the info I am looking for. Thanks. So far I am loving your site.