Simple experiment to do at home that involves acids and bases? so long story short I am in the IB Diploma and I am required to come up with an experiment to investigate pretty much anything to do with chemistry. I'm thinking about doing mine on investigating how temperature affects the pH value of a solution, but my teacher said it was too simple.

Basically, is there any reaction I can make at home with simple chemicals(vinegar, baking soda, salt, juice, etc.) that would produce a meaningful experiment and involves me measuring the pH level? Thank you guys so much.
Measure the pH+ of various foods, and make a spreadsheet listing them.

You might also measure pH+ change with time in a food, e.g. apple juice or bread dough, with a few mg of yeast sprinkled in.