Do we need acid in our stomachs to digest food?

To finish off our Science topic, ‘Eating and Digestion’, we carried out an experiment to answer the question, ‘Do we need acid to digest food?’

To do this, we needed the following pieces of equipment:

Two sealable freezer bags (the stomach)
Two slices of bread (the food)
One glass of orange juice (the stomach acid)
One glass of water

To start with, we used our hands to break the bread into smaller pieces. Our hands acted as the very first stage of the digestive process, our mouths and teeth!

We then dropped the pieces of bread into our stomachs and poured in either a small glass of orange juice or a small glass of water.

After that, we used our hands to act like our stomach muscles – contracting and mixing the contents.

We discovered that the food that had been mixed with water did not break down, but the food that had been mixed with the acidic orange juice did break down. This proved to us that we do need acid to break down the food in our stomachs.