cream of tartar, permissible?

Dr. Mohamad Naim Mohamad Hany Saei Member of the Permanent Fatwa Committee (AMJA), he said: Every honourable Muslim should stay away from this ingredient because it came out of an unlawful source as its crystallization or precipitation is the result of unlawful processing (fermentation of grape juice), especially that these results occurred after the fermentation, not before it.