Place the corn kernels, jalapeño and bay leaf into a 16-ounce jar.
Using a small pot, combine the vinegar, water, sugar and kosher salt. Place on the stove on high heat and bring mixture to a boil. Once mixture is boiling, remove from the heat and pour into the jar. Any extra pickling liquid can be discarded.
Place the lid on top of the jar and allow it to cool off until room temperature. Once the jar is cool, place it into a cool place like the fridge and leave to chill overnight.