A simple method of assessing the viability of a lactic starter culture is presented. The method is based on the kinetics of growth of a culture during the lag and early exponential phases. The microorganisms used throughout this work were Lactobacillus spp. The method was tested with inocula samples of different ages and with samples taken during chemostat runs, at different dilution rates. The results obtained are similar to ones describes in the literature for similar situations. The method is very easy to operate once the intrinsic parameters have been established (χmax and μmax). It needs only standard laboratory equipment and is very economical.