Why is ‘cabbage juice’ in the STEM section? 

Because red cabbage juice (and beet juice) can be used to measure the pH level in liquids. 

This is science, as surely as Soda n' Vinegar volcanos are science. 

pH is what classroom volcanos are all abut.

Red vegetables have ‘anthocyanins’ in them. 

A very primitive test for pH uses ‘litmus paper’.  I used limus paper in High School Chemistry, decades ago.

And if you have white coffee filters, and red cabbage or beets, your Adults can help you make litmus paper. 

Litmus paper is a safety device, for it tells us how acid or how base (alkaline) a liquid is, which tell us how pH-safe liquids are. 

Litmus paper tells us how acid or base (alkaline) a liquid is by what color the litmus paper turns when wetted.

Instructions are at the website link below. Have an adult supervise. Really!    Have fun. 

https://kitchenpantryscientist.com/science-meets-art-red-cabbage-litmus-paper/ 

Also, take a good look at the pattern in the cabbage, then do an image search for 'fibonacci pattern cabbage'

and learn a little more

Eric J. Rose 

middlegrademysteries.com 

photo: EJR