Slow cook for large quantity foods must consider whole tank even heated issue. We use ultrasonic vibration technology for this task. Even this 250L machine is fully loaded with food bags, tiny bubbles created by high frequency ultrasonic vibration can bring heating to every where. Moreover cavitation effects will do rubbing effect helping for better tasting. If ultrasonic power is enough, it can tenderise hard tissue. So our patent application with ultrasonic to Sous vide slow cook is advanced technology in culinary field. Good machines for central kitchen, or large food processing factories.