Yogurt is a functional food that has recently become popular in Indonesia. Making yogurt requires a starter culture, which can be found in liquid or powder form in microencapsulated form. This powdered yogurt starter will be applied using back-sloping fermentation for the practicality of the yoghurt-making process. This research aimed to determine how many cycles the back-sloping fermentation using microencapsulated yogurt (MY) starter was applied and evaluate the quality of yogurt in each back-sloping fermentation cycle. The lactic acid bacteria contained in MY starter were Lactobacillus plantarum TMW 1.1623 and Streptococcus thermophilus in a 1:1 ratio. The research results showed that yogurt made from ultra-high temperature milk UHTM had a water content of 84.18–86.12%, protein content of 3.52–3.78%, a fat content of 3.34–3.38%, pH 4.72–5.05, titratable acid (TTA) 0.74-1.24%, total lactic acid bacteria (LAB) 7.69–12.07 log CFU/mL, viscosity 285.15–2417.9cP, and Syneresis 0.00-0, 14%. Yoghurt made using fresh cow’s milk (FCM) had the following characteristics: water content 84.02–86.18%, protein content 3.43–3.74%, fat content 3.32–3.38%, pH 4.13–4.44, TTA 1.77-2.06%, total LAB 10.32–10.76 log CFU/ml, viscosity 2430.15–4497.55cP, and Syneresis 0.00−0.07%. This research concluded that using MY starter for making yogurt using the back-sloping fermentation method could be used for up to seven and nine cycles for yogurt made from UHTM and FCM. The yogurts produced all meet probiotic drink standards with LAB content exceeding WHO standards, namely LAB content of more than 7 log CFU or 107CFU/ml.
Keywords | Starter, Lactic acid bacteria, Yogurt, Back-sloping fermentation