Fun Things to Do with pH

Waldorf education typically includes this topic in grade 7/8 Chemistry. In fact, one of my favorite Live Education! sample lessons is the grade 8 Chemistry of the Limestone Cycle illustration:

Although public schools very often introduce pH, litmus paper, and acids & bases much earlier, Waldorf waits until students are old enough to put that information into specific chemical reaction formulas that explain natural phenomena (for example, acid rain, the Nitrogen cycle, the formation of quicklime, etc.). They are also old enough to understand a logarithmic scale.

(For a vivid description -- and visual -- of quicklime formation, I recommend Edwardian Farm, episode 1.)

What is acidic? What is alkaline?

0 - battery acid

1 - toilet bowl cleaner

2 - lemon juice

3 - vinegar

4 - acid rain

5 - black coffee

6 - milk

7 - pure water

8 - sea water

9 - baking soda

10 - borax

11 - ammonia solution

12 - oven cleaner

13 - bleach

14 - lye

pH comes up in Dyeing with Natural Dyes and Soapmaking, both great options for the 7th grade Waldorf Practical Life curriculum.

The Complete Guide to Natural Soap Making
by Amanda Gail Aaron

Note: If you don't want to actually do soapmaking or whitewashing, there are some wonderful descriptions in Farmer Boy by Laura Ingalls Wilder.

whitewash
"The Turn of the Year," p.119

soft-soap
"Cold Snap," pp.164-165
"Saturday Night," pp.80-83

At whatever age you choose to study pH with your child, I think that it can be so helpful to have a variety of ways to go about it. This way, if you need to revisit it later on in a fresh way, you have options! Here are some I like; please feel free to share more in the comments!

Lemon Volcanoes
This is super-fun but quite messy; I highly recommend doing it on a rimmed baking sheet or, if you have one, an old cafeteria tray.

Baking Soda Paint
Since this reaction leaves a fuzzy texture, it is perfect for painting peaches! (I like to use this template. Print it, cut it out, and use that to trace a peach shape onto your watercolor paper. Then cut out the watercolor paper shape.)

Miracle Berry and the Science of Taste (PDF)
We did this in our first session of Science Club: Weather this fall, to lead into a discussion of pH (and acid rain). The children really enjoyed it.

Make Poinsettia pH Paper
A perfect post-Christmas Science project!!!

Natural Dye Using Turmeric
Rebecca Desnos medicinal plant dyeing email
Jan 5, 2023
"Turmeric is highly sensitive to alkali, so if you wash [your dyed fabric] with regular soap then it will turn bright red, which is quite spectacular to see! Wash with pH neutral detergent or just rinse in plain water. Alternatively, you might enjoy playing around with the pH sensitivity of turmeric and paint patterns with alkali water (water with baking soda dissolved)."

Heritage Park Silk & Wool All-Natural pH-Neutral Laundry Detergent

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