This work presents the biospeckle laser technique as a potential tool to analyse the kefir grains activity. In the present work, the kefir grains biological activity was measured from quantitative measurements by means of their speckle activity. The aim was to show that the biospeckle laser is a potential methodology to assess kefir grains viability, monitoring the kefir grains during the beverage production. The monitoring of the activity of the kefir is a key factor to guarantee the efficiency of the production of beverages, however the routine ways it is done compromise its use in the online production. The kefir grains were illuminated by a laser HeNe 17 mW 632 nm and analysed by the numerical biospeckle laser method. The results presented the statistical separation of the kefir in distinct levels of activity as expected. This can be an innovative technique to be used in the beverage industries for kefir grains inoculum control.