Plant‐Based Kefir From S arıkılçık Rice Milk: A Multi‐Level Evaluation of Physicochemical, Sensory, and Microbial Features

ABSTRACT This study investigates the potential for developing a dairy‐free, functional kefir using Sarıkılçık rice ( Oryza sativa L.), a traditional Turkish variety cultivated in Kastamonu. Kefir was produced by fermenting rice milk with water kefir grains at three inoculation levels (2%, 5%, and 9%) and was then evaluated in comparison with traditional milk kefir and a commercial kefir product. Comprehensive assessments included physicochemical measurements (pH, dry matter content, titratable acidity, and color), sensory evaluation, and metagenomic profiling via high‐throughput 16S rRNA sequencing. Among the rice kefirs, the 9% inoculated rice kefir exhibited the lowest pH of 3.56 and the highest lactic acid content, along with darker and more green‐blue color values. Although traditional and commercial kefirs had higher sensory acceptability, rice kefir with 9% inoculation emerged as the best plant‐based option. Metagenomic results showed Lactobacillus ghanensis dominated rice kefirs, while Lactococcus kefiranofaciens was abundant in commercial kefir. Microbial diversity was highest in traditional kefir, followed by commercial and rice kefirs. The highest diversity index among rice kefirs was found in those inoculated with 5%, 9%, and 2% water kefir, respectively. Rice milk showed the lowest microbial richness. These findings demonstrate the potential of water kefir fermentation as a promising approach for developing microbiologically diverse and plant‐based kefir alternatives. Integrating sensory, chemical, and microbial data provides valuable insight for future optimization and industrial applications.