Describe the method of manufacturing, packaging and storage of butter.

Manufacturing of Butter

The process of butter manufacturing involves several key steps, beginning with raw milk and culminating in the final product. The core principle involves agitating cream to cause the fat globules to clump together.

Churning Process

1. Milk Reception and Standardization: Raw milk is received, tested for quality, and standardized to achieve a fat content of approximately 40-42% for cream.
2. Cream Separation: Milk is centrifuged to separate the cream from the skim milk. Modern dairy plants employ disc-stack centrifuges for efficient separation.
3. Cream Ripening (Optional): In traditional butter making, cream is ripened by allowing naturally occurring bacteria to ferment the lactose, producing lactic acid. This contributes to the characteristic flavor of cultured butter. Pasteurization is now more common to ensure safety and consistency.
4. Churning: The cream is agitated vigorously in a churn. This mechanical action breaks down the membranes surrounding the fat globules, causing them to coalesce and form butter granules. Modern churns are often automated and temperature-controlled.
5. Washing: The butter granules are washed with cold water to remove residual buttermilk, which contains lactose and contributes to spoilage.
6. Working (Kneading): The washed butter granules are worked or kneaded to expel excess water and develop the desired texture and plasticity. Salt may be added during this stage.
7. Grain Out: Butter is passed through a grain out to remove any remaining water and whey.
8. Packaging: Butter is then ready for packaging.

Packaging of Butter

Packaging plays a vital role in preserving the quality and extending the shelf life of butter. The packaging material must be impermeable to moisture, light, and oxygen.

Packaging Materials

• Wax Paper: Traditionally used, offering good moisture barrier properties.
• Aluminum Foil: Provides excellent barrier against light and oxygen, preserving flavor and color.
• Polyethylene (PE) Films: Commonly used for laminations, offering good flexibility and sealing properties.
• Polypropylene (PP) Films: Used for their strength and heat resistance.
• Multi-layer Films: Combinations of the above materials are often used to achieve optimal barrier properties. For example, a laminate of PE/Aluminum Foil/PE.

Packaging Formats

• Blocks/Rectangles: Common retail format.
• Rolls: For foodservice and baking applications.
• Portion Packs: Individual servings for convenience.
• Vacuum Packaging: Extends shelf life by removing oxygen.

Storage of Butter

Proper storage conditions are critical for maintaining the quality, flavor, and safety of butter.

Storage Temperature

• Refrigeration (0-4°C): Recommended for most butter types to extend shelf life and prevent spoilage.
• Freezing (-18°C or below): Butter can be frozen for longer storage, but it may experience some changes in texture upon thawing.

Storage Conditions

• Darkness: Butter is susceptible to light-induced oxidation, which can cause off-flavors.
• Moisture Control: High humidity can lead to mold growth.
• Air-tight Packaging: Reduces oxidation and flavor loss.

Parameter	Refrigerated Storage (0-4°C)	Frozen Storage (-18°C or below)
Shelf Life	2-3 months	6-12 months
Texture	Relatively stable	May become slightly crumbly upon thawing
Flavor	Maintained well	Slight flavor changes possible