A batch freezer with fast and safe blocking and opening comprising a front wall (11) provided with an access or closure flange (12) for an opening (13) positioned in the front in a freezing cylinder (14), a hopper (15) for the insertion of ingredients for the production of ice cream, positioned above the flange (12) and a gridded door (16) for extracting the finished product beneath the flange (12), the flange (12) being positioned on a closing crosspiece (17) articulated with a pin (20) at a first end to the front wall (11), and at a second end carrying a blocking lever (18), wherein a safety blocking-unblocking group (19), which serves for blocking the access flange (12) to the freezing cylinder (14), is associated with the closing crosspiece (17) near the blocking lever (18), a sensor being provided on the one hand connected to a microcontroller which switches off the motor of the batch freezer and removes the power supply from the blocking-unblocking group (19) so that, after a prefixed time, the flange (12) is released to allow the closure of the opening (13) and on the other hand, the sensor communicates to the microcontroller, the pressing of a stop button (50) with the handle closed, so that the microcontroller, after a settable time, sends a release command to the blocking-unblocking group (19) allowing the flange (12) to be released for closing the opening (13).
