How do you know? How long does it take?
I bought a half gallon of So Delicious coconut milk which is soy-based. It was 50 cents because it has passed its sell by date of Sept 4th by two days.
I wanted to try this, so for 50 cents I didn't care if it went bad soon.
I finished the last of it today, 10 days after its sell by date. It tasted no different than day 1. On top of it, the fridge I'm using isn't particularly good ... I had to throw out a lot of food ... not the So Delicious.
Is this stuff like Twinkies? Does it ever go bad?