Growth Characteristics of Kefir Grains and Kefir Starter

Growth characteristics of kefir grains,microflora of kefir starter and the optimum ferment conditions for making kefir starter and yogurt were studied.The growth characteristics and the optimum ferment conditions of kefir grains were determined by pH of fermented milk and quality of kefir grains.Kefir starter's microflora was determined by combining with colony characteristics and cell shapes.Results show: When kefir grains preserved at-18 ℃ was used to make yogurt,it was necessary to activate.When kefir grains were activated to the ninth generation,it could be best.The best conditions were to inoculate kefir grains in sterilized pure milk with the 1 ∶ 8(g/mL) ratio,and culture at 28 ℃ for 24 h.The microflora in kefir starter included Lactobacillus,Leuconostoc,Pediococcus,and Sporolactobacillus.Using kefir starter to make yogurt,the ferment temperature should reach 37 ℃.