Gracie squeezed some grapes and kept the juice in a vessel for 5 days at room temperature. On the fifth day she found that the juice tasted sour and appeared frothy.
What caused this change?

Question

Gracie squeezed some grapes and kept the juice in a vessel for 5 days at room temperature. On the fifth day she found that the juice tasted sour and appeared frothy.
What caused this change?

anonymous · Answer

Sounds like fermentation to me - acid is produced giving the sour taste and CO2 is produced too - hence the froth. Wild yeast in the air will do the job - only a few are needed to start but they keep on growing in the right environment. Some grapes have yeast on them to start fermentation.

anonymous · Answer

what kind of formation