9-volt batteries have positive and negative terminals on one end, so it's possible to feel electrical current by placing that side on a body part. If this body part is the tongue, one can taste the experience.
(Or so I have read.)
The Verge reports that Rewind, a European company, is releasing several corn chip flavors, among them conventional flavors such as paprika and sriracha. The brand wants to inspire nostalgia and has therefore decided to also issue a flavor that tastes like battery.
Dominic Preston agreed, presumably under duress, to test the new flavor. He found that the chips do indeed taste like a battery--a flavor created with baking soda and citric acid.
-via Dave Barry