Fermented milk can turn into a variety of products, including alcoholic milk and moldy milk, depending on the microorganisms involved in the fermentation process.
Types of Fermented Milk
Fermented milk products result from the activity of lactic acid bacteria (LAB) and, in some cases, yeasts and molds. The specific types of microorganisms used lead to different end products. Here's a breakdown based on the reference provided:
Alcoholic Milk
- Kefir: A tangy, slightly effervescent beverage made with kefir grains containing a symbiotic culture of bacteria and yeasts.
- Koumiss: A traditional Central Asian drink made from mare's milk, also fermented using a mix of bacteria and yeasts.
- Acidophilus-yeast milk: Similar to kefir and koumiss, this milk is fermented by both acidophilus bacteria and yeast.
These products are characterized by their alcoholic content, which is a result of the yeast fermentation process, in addition to lactic acid fermentation which gives it a tangy flavor.
Moldy Milk
- Viili: This Finnish fermented milk is characterized by a unique, ropy texture and a mild, slightly acidic taste, due to molds along with LAB.
The Fermentation Process
According to Khorshidian et al. (2020) and Tamang et al. (2016), fermented milks often involve fungal-lactic fermentations. This means that the fermentation process is carried out by both LAB and yeasts (in the case of alcoholic milks) or molds (in the case of moldy milks). These microorganisms break down lactose (milk sugar) and other compounds, producing lactic acid and other byproducts which lead to the specific characteristics of each fermented milk product.
Type of Fermented Milk | Microorganisms Involved | Key Characteristics | Examples |
---|---|---|---|
Alcoholic Milk | LAB and Yeasts | Tangy, slightly alcoholic, effervescent | Kefir, Koumiss, Acidophilus-yeast milk |
Moldy Milk | LAB and Molds | Ropy texture, mild taste | Viili |
Conclusion
Fermented milk, through the action of various microorganisms like lactic acid bacteria, yeasts, and molds, can be transformed into a wide variety of products including alcoholic beverages such as kefir, koumiss, and acidophilus-yeast milk, and moldy products like viili. These transformations yield diverse flavors, textures, and nutritional profiles.