Blog of Jonathan Eisen, Professor at UC Davis, Open Science advocate, Guardian of Microbial Diversity, Fighter of #Badomics Words and Microbiomania , and YAMMMs . Plus lots more things. See Lab Page and Twitter @phylogenomics for more info.
My mom has sent instructions for using red cabbage to do pH testing at home:Boil red cabbage in a small amount of water. Cool, and use the liquid to test household items like vinegar, lemon juice, baking soda, etc.(Its even better if you extract in alcohol but not as safe.)