Kefir is a fermented milk product in which lactose fermentation takes place through the simultaneous action of bacteria and yeasts. Regardless of the production method (traditional/industrial), the final product of fermentation consists of lactic acid, gas (CO2) and variable amounts of isoamyl and ethyl alcohol. Traditional kefir production is based on natural fermentation processes using kefir grains and is often associated with cultural traditions, while commercial kefir production involves strictly controlled processes, standardized dairy cultures and modern production techniques to meet market demand for a standardised product in terms of consistency and longer shelf life from a sustainability perspective. While the fermentation process itself is the same for both traditional and commercial kefir production, their approaches differ significantly in terms of the origin of the culture used, the fermentation method, the handling of the final product and the distribution strategy. These differences reflect the balance between tradition and modernity when it comes to meeting the demands of today's consumer market. Through a review of available literature sources, the article shows the differences in kefir depending on the production method.