Jammed Jar Spigot

I was experimenting with a continuous brew injera (Ethiopian sourdough pancake) and it was doing excellently dispensing the 1st time. When I dispensed enough I wiped the mouth and that was it, I didn't poke my cloth into the mouth. However, the 2nd time I tried to dispense, it ran for several moments perfectly fine then suddenly stopped flowing. I mixed the batter mixture around in the jar especially where the spigot inlet was located and still nothing flowed out. The spigot is plastic and has a knob that must be turned counterclockwise 90deg to flow. The viscosity of the mixture was somewhat runny.

Is there a fix that I can perform without taking out the injera batter mixture?