Fermented dairy products have been a part of human diets since as early as 10,000 B.C. They are produced by introducing beneficial bacteria into milk, leading to a range of products with improved digestibility, unique flavors, and extended shelf life. As a food processing consultant or food manufacturing consultant, understanding the fundamentals of milk fermentation is essential for optimizing dairy product development.
What is Fermentation in Dairy?
Fermentation is a metabolic process where microorganisms such as Lactobacilli and Bifidobacteria partially digest milk sugars (lactose), converting them into lactic acid. This natural transformation:
- Enhances the taste and texture
- Increases shelf life
- Improves nutrient absorption
- Introduces probiotics for gut health
This process is widely used in food technology consulting to design safe, functional dairy products.
How Fermentation Works in Dairy Processing
- Microorganisms break down sugars like glucose for energy.
- In the absence of oxygen, they switch to anaerobic fermentation.
- This process yields lactic acid, which lowers pH and helps coagulate milk.
- The result is a sour-tasting, thicker product that resists spoilage.

Types of Fermented Dairy Products
Fermented milk, also known as cultured dairy, is made using specific lactic acid bacteria (LAB). These bacteria thrive in nutrient-rich milk environments and help preserve the product while enhancing nutritional value.
Here are some widely consumed fermented dairy products:
1. Dahi (Curd)
- Made via bacterial fermentation of milk.
- Uses "dahi cultures" for fermentation.
- Fat content requirements:
- 1.5% for double-toned milk
- 3.0% for toned milk
- 3.2% for cow milk
2. Shrikhand
- A semi-solid, sweet-sour dessert popular in western India.
- Made from curd (dahi) and has a shelf life of 40 days at 8°C.
- Common during festive occasions.

3. Buttermilk
- Liquid byproduct of curd churning.
- Can be plain, salted, or spiced.
- Shelf life: 7 days under refrigeration.
4. Cheese
- Produced by separating curds and whey.
- Curds are aged, pressed, and often salted.
- Common bacteria used:
- Lactococcus lactis
- Streptococcus thermophilus
- Lactobacillus strains
Industrial Production Example: Shrikhand
Shrikhand is an excellent example of food factory design and food consultancy services applied to traditional dairy:
Step-by-Step Process:
1. Milk Preparation
- Use cream separator to get high-fat cream (70%+) and fat-free skim milk.
2. Pasteurization
- Skim milk: 90°C for 10 mins
- Cream: 85°C for 16 secs
3. Inoculation
- Add 0.5% lactic starter to skim milk in a sterile vat at 30°C.
4. Incubation
- Maintain 30°C for 8 hours until acidity reaches 0.8–1.0%.
5. Whey Separation
- Centrifuge to obtain chakka (solids).
6. Mixing
- Combine chakka with cream and sugar (target: 6% fat, 42% sugar).
7. Flavoring and Packaging
- Add desired flavors.
- Package in sterile cups and refrigerate.
This process showcases how project management in food processing plants ensures standardization, quality, and food safety.

Benefits of Fermented Dairy Products
- Improved digestion and gut health
- Increased bioavailability of calcium and minerals
- Suppression of harmful bacteria
- Better shelf stability of milk-based products
These advantages make fermented products a focus for food business consultancy and R&D in dairy technology.
Conclusion
Fermented dairy products like curd, buttermilk, shrikhand, and cheese are crucial in today’s food manufacturing and consultancy for food industry. Using food industry consultants, brands can achieve consistent quality, hygiene, and compliance with global food safety standards.