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.
Yes and if you pour the juice from cooking red cabbage onto eggs whilst frying it turns the egg whites green too