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Microbial screening is a primary concern for many products. Traditional techniques based on standard plate count (SPC) are accurate, but time consuming. Furthermore, they require a laboratory environment and qualified personnel. The impedance technique (IT) looking for changes in the electrical characteristics of the sample under test (SUT) induced by bacterial metabolism represents an interesting alternative to SPC since it is faster (3–12h vs. 24–72h for SPC) and can be easily implemented in automatic form. With this approach, the essential parameter is the time for bacteria concentration to reach a critical threshold value (about 10⁷cfumL⁻¹) capable of inducing significant variations in the SUT impedance, measured by applying a 100mV peak-to-peak 200Hz sinusoidal test signal at time intervals of 5min. The results of this work show good correlation between data obtained with the SPC approach and with …