A beverage dispenser for dispensing beverages and process may include a fluid container containing a fluid ingredient, a conduit fluidly connected to the fluid container, and an electrical conductivity sensor. The electrical conductivity sensor may be (i) fluidly connected to the conduit, and (ii) configured to sense an electrical conductivity of the fluid ingredient flowing through the conduit. The electrical conductivity sensor may further be configured to output (i) a first electrical signal in response to sensing an air bubble, and (ii) a second electrical signal in response to not sensing an air bubble.