What is Happening?
he electric pickle is a classic demonstration of electrical conductivity of a salt solution. The pickle is filled with a salt solution that can conduct an electrical current.
When 110 Volts are applied to the pickle, current will flow through the salt solution. As the current flows, the solution will begin to heat up locally and eventually boil away. This then creates a small insulating pocket. Sometimes, the voltage can arc over this region and create a visible spark. More solution may drip into this region making it conductive again and restarting the process.
If heated for too long the pickle juice will all boil away and the pickle will no longer “light up”.