There are lots of questions like this....
You did not specify if you are talking about ayahuasca vine or prepared ayahuasca tea.
Ill assume tea, if it is not moldy or very smelly, then it is still good. I have drank aya tea that has been sitting in fridge for over 1 year, and it was still fine, tasted fine, and did not lose potency.
It can mold though, and if it does it is lost.
Dry vine, or any of the plant material we work with, stays good for many years, and if properly stored, potentially a lifetime.
Good luck and good vibes your way,
You have never been apart from me. You can never depart and never return, for we are continuous, indistinguishable. We are eternal forever