The studies were conducted to determine the effect of water extracts of selected herbs on the growth of yeast (Saccharomyces cerevisiae) colonies. The medium was brewery wort solidified with agar and enriched with 1 cm³ of herbal extract. The growth of colonies was measured after incubation at 30°C for 48 h. The salvia and polygonum extracts had positive effect on the growth of colonies of brewery yeast, increasing their diameter by 45-75%. The same was true for the effects of salvia and calamus extracts on the growth of bakery yeast. In contrast, the extracts obtained from aloe, calamus, and thyme, had strong and statistically significant inhibitory effect on the growth of distillery yeast, reducing the diameter of colonies by 21-62%. The commercially available dry herbs (mint, polygonum, camomile and angelica) showed microbial contamination, mainly with bacterial microflora (39-93·10⁴ colonies /1 g).