I took this photo of the water after I’d steamed some red cabbage at the weekend because I thought it was such a beautiful colour.
And then I got to wondering what chemistry is going on that means that a lovely deep red cabbage produces blue water (with slight hints of green – it was bluer in reality than the picture shows – more photography practice for me). It turned out to be pretty simple and a quick bit of googling lead me to the answer.
It’s all about the pH of the water – and in fact red cabbage isn’t always red depending on the acidity or otherwise of the soil it’s grown in. I then found a chart of the most recent water tests for the area where I live on the Thames Water site – how cool is this – you put in your postcode and it takes you to the stats for your area – oh such delightful push of button geeky info.
And on about.com I found a table that tallying the water colour to the expected pH – which was pretty accurate an estimated pH 8 compared to measured average of 7.8. I’m impressed (some might suggest its easily done but hey).
Science made interesting? Maybe.