Creatine should have a mild sour smell to it but it should not wreak like ammonia or anything like that.
Creatine monohydrate should have a neutral taste in water. If you mix the creatine in water and it tastes extremely acidic, your creatine as returned rancid. Throw it out. Creatine supplements are very cheap. It's not worth possibly getting sick.
The problem with bulk creatine powders is that even if a very small amount of water leaks into the container, it can cause bacteria to grow and make the product rancid. I like to use a capsulated creatine product like ancient strength from n2bm.com for that reason. It's also way easier to dose. No pills or scoops. Just 3 pills per day.