Batteries taste sour but most adults recommend you not to taste any batteries by sticking it with your tongue because as you will cause acute tissue damage to your mouth. When you touch the battery with your tongue, you might feel shocked and might have noticed the battery taste sour. But why does the shock have a flavor?
Is it the acid or anything else that taste sour?
You might think the sour taste is caused by the battery acid but actually, it wasn’t the battery acid it was the taste of the electric current from the charged battery. Here is the reason electric current taste sour,
You don’t feel shocked when you touch the little knob with your hand because your skin doesn’t conduct electricity well enough for a current to flow. But when you touch with your tongue, your saliva has no trouble conducting electricity well enough to make a circuit. Thus, the electron flowing out of one lead and into the other creating an electric current. On the way, they can interact with the water molecules and basically rip them apart in a process called electrolysis.
The current which enters your saliva from one lead creates hydrogen gas leaving hydroxide ions behind and current leaving your saliva through the other lead creates oxygen gas leaving hydrogen ions behind. And these hydrogen ions are the ones that make sour taste.