In a full-automatic yogurt production line, the yogurt starter is a specific microorganism culture material used to make yogurt. The role of the starter in the production of yogurt is very important, which is the basis and main reason for the acid and aroma production of yogurt products. Therefore, the quality of yogurt mainly depends on the quality of the yogurt starter. So what should you pay attention to when making frozen yogurt with the yogurt starter?
What is the yogurt starter?
Yogurt is made from fresh milk, fermented under appropriate temperature and anaerobic conditions after inoculation with lactic acid bacteria. After the yogurt is fermented, the original lactose is partially converted into lactic acid, but a part of the lactose is still retained, so a unique sweet and sour flavor is formed. The key to ferment yogurt is to choose the appropriate yogurt starter.
Yogurt starters can be divided into three types according to different physical forms: liquid yogurt starter, frozen yogurt starter, and direct-injection yogurt starter. Liquid yogurt starter is cheaper, but the vigor of bacteria often changes, it is easy to be stained with bacteria during storage, and the storage time is short. When this kind of starter is transported over long distances, its viability decreases rapidly.
Frozen yogurt starter is deep-frozen, its price is cheaper than the direct-injection yogurt starter, its strains have higher vitality, and its activation time is shorter, but it needs to be transported and stored under special environmental conditions around -45℃to -55℃.
The direct-injection yogurt starter can not only be directly put into the fermentation tank to produce yogurt, but also can be stored in ordinary refrigerators, the transportation cost and storage cost are very low, and its convenience, low cost, and stable quality during use are particularly prominent.
Precautions for making yogurt with yoghurt starter
- Pay attention to choosing the right raw materials
If you want to use the yogurt starter to make yogurt, you must use pure milk, and you can’t add anything to the milk. And yogurt machine manufacturers found that most of the milk on the market is made into beverage-like products of various flavors. In order to meet people’s different tastes, a lot of other substances are often added to milk, so it cannot be used as the raw material for making yogurt. Also, lactose-free milk cannot be used when making yogurt.
- Pay attention to control the temperature
In the process of making yogurt, you must try to make the lactic acid bacteria active, so it is necessary to provide some calories from the outside as an intervention. Therefore, when the yogurt is fermented, the temperature must not be too low but not too high, otherwise, it will kill the lactic acid bacteria and cause no way to ferment. Therefore, the yogurt-making machine manufacturer emphasizes that the temperature of milk heating must be paid attention to, and users can use special electrical appliances to keep heat, otherwise, they must think of a certain way to keep it warm.
- Choose the right container and pay attention to disinfection
The container chosen by the user is also critical for making yogurt. The container must be sufficiently clean. If the user chooses a plastic cup, it is necessary to avoid using a container that will deform after heating and keep it closed. Therefore, it is better to choose a lid. Otherwise, if too much oxygen is left open, it will affect the fermentation of lactic acid bacteria. And the container should be thoroughly disinfected before pouring into the milk. Generally, boiling with water is better than using disinfection water.