Yogurt Making as a Tool To Understand the Food Fermentation Process for Nonscience Participants

Designing an outreach program concerning food fermentation for nonscience participants offers an opportunity to introduce the basic principles of microbiology and their application in food preservation. This program can be adapted to microbiology courses at the undergraduate level to help students understand the concept of food fermentation and its process control. Yogurt is a type of fermented milk that is commercially available in Indonesia. While yogurt fermentation is usually performed in a closed fermenter in an aseptically controlled room, yogurt can also be made at home using lactic acid bacteria culture starters, such as Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus, and applying proper hygiene and sanitation procedures. Yogurt making requires not only appropriate ingredients but also an understanding of the microbiological concepts of yogurt fermentation in order to enable control and modification of the fermentation process so that the end product is safe to consume. Through this activity, we provided training to residents from a nonscience background in Bogor, Indonesia, for simple and feasible homemade yogurt production using a variety of milk substrates and sources of starter culture. All participants prepared the ingredients and sanitized kitchen equipment, performed the yogurt fermentation process, and evaluated the product's sensory properties. Participants were challenged to explore the differences among various yogurt batches. This activity can be completed in two days, and the recipe could be modified once the participants have understood the concept of yogurt fermentation.