A batch ice maker can execute a pulsed fill routine in which a control system pulses water from a water supply into the sump until the sump reaches a predefined freeze routine starting level. Pulsing may begin after continuously filling the sump to a fill-approach level. A batch ice maker can execute a differential freeze routine in which the control system circulates water from a sump to an ice formation device until water level decreases by a predefined differential amount from a high control water level based on the water level in the sump at a point in time after the sump was filled to a freeze routine starting level. The high control water level can be set based on water level in the sump when sump water temperature reaches a predefined pre-chill temperature. The predefined pre-chill temperature can be associated with a switchover from sensible cooling to latent cooling.