Pembuatan Yoghurt/Yoghurt Probiotik/Produk Fermentasi/Olahan Susu/Starter/Lactic acid bacteria

Summary

In this video, the process of making yoghurt from fresh milk is demonstrated in a microbiology lab at Universitas Padjadjaran. It covers essential steps such as sterilization, pasteurization, and inoculation with starter culture. The video also explains different methods of pasteurizing milk, followed by cooling, before adding the starter to initiate fermentation. The impact of varying milk types and starter concentrations on the yoghurt's texture, aroma, and consistency is explored, showing how these factors influence the final product. The result is a rich, informative guide for making homemade yoghurt with clear explanations and visual demonstrations.

Takeaways

• 😀 The video focuses on the process of making yogurt from fresh milk, emphasizing the importance of sterilization, pasteurization, and fermentation.
• 😀 Sterilization is done using hot water at 100°C for 15 minutes to clean the jars and equipment needed for yogurt production.
• 😀 Two pasteurization methods are discussed: heating the milk on a hot plate or on a stove, both reaching 85°C for 15 minutes.
• 😀 Gula pasir (sugar) is added to the milk during pasteurization, and a magnetic stirrer is used to ensure it dissolves completely.
• 😀 After pasteurization, the milk is quickly cooled to 40-45°C by immersing the container in cold water to prepare it for fermentation.
• 😀 Starter culture is added to the cooled milk, with two concentrations: 3% and 5%. The amount of starter is determined based on the milk volume being fermented.
• 😀 The mixture is then placed in sterilized jars, with each jar containing around 200 mL of milk for fermentation.
• 😀 The fermentation process takes around 6 hours, during which the milk thickens and develops the typical yogurt texture, aroma, and taste.
• 😀 Yogurt made from skim milk with a 3% starter concentration has a consistency similar to a liquid, while increasing the starter concentration results in a thicker consistency.
• 😀 Full cream milk, when fermented with 3% or 5% starter, produces yogurt with a thicker consistency and a stronger yogurt flavor, making it more spoonable.
• 😀 The quality of yogurt is influenced by both the type of milk used (skim or full cream) and the starter concentration, with higher starter percentages leading to thicker yogurt.

Q & A

What is the first step in the yogurt making process mentioned in the video?

The first step is the wet sterilization process, which involves boiling water at 100°C for 15 minutes to sterilize the equipment, including jars used for making yogurt.

Why is it important to use a large pot for sterilization?

A large pot ensures that there is enough space for the water to cover the jars completely and allows for proper sterilization of all the equipment.

What materials are needed to make yogurt as mentioned in the video?

The ingredients for making yogurt include sugar, fresh cow's milk (both full cream and skim), and a commercial starter culture.

What is the purpose of pasteurizing milk in yogurt production?

Pasteurization helps to eliminate harmful bacteria in the milk, making it safe for fermentation, and also helps to improve the consistency and flavor of the yogurt.

How is pasteurization done in the video?

Pasteurization is done by heating the milk to 85°C using either a hot plate or a stove, then maintaining the temperature for 15 minutes. Afterward, the milk is cooled down to 40-45°C.

What are the two methods for pasteurizing milk shown in the video?

The two methods for pasteurizing milk are: 1) heating the milk on a hot plate until it reaches 85°C and maintaining the temperature for 15 minutes, and 2) heating the milk on a stove in a pot, following the same procedure.

How is the sugar dissolved in the milk during the pasteurization process?

Sugar is dissolved by adding it to the milk after it reaches 85°C, and then using a magnetic bar to stir the mixture until the sugar is fully dissolved.

What is the temperature range that the milk should be cooled down to after pasteurization?

The milk should be cooled to a temperature between 40-45°C after pasteurization to prepare it for fermentation.

What happens during the inoculation step in yogurt production?

During inoculation, the starter culture is added to the pasteurized milk, with different concentrations (3% and 5%) of the starter being used to initiate the fermentation process.

How does the concentration of the starter affect the texture of the yogurt?

The higher the concentration of the starter culture, the thicker and more consistent the yogurt will be. For example, a 5% starter concentration produces a thicker texture than a 3% starter concentration.

What were the results of the yogurt fermentation in the video?

After about six hours of fermentation, the results showed that yogurt made with skim milk and 5% starter was thicker than that made with 3%. Full cream milk produced yogurt with an even thicker texture, especially with a 5% starter concentration.