Introduction to Butter Production Process

Introduction to Butter Production Process

The butter production line is an automated system integrating mechanical, chemical, and food science technologies, aiming to efficiently and hygienically transform raw milk (usually cream) into commercial butter.

We will provide a detailed introduction from two aspects: the production process flow and core equipment.

I. Butter Production Process Flow

Butter is essentially milk fat. The core of the production process is to break down the fat globules in cream, allowing the fat to aggregate together and separate from the water (buttermilk). Modern industrial production mainly adopts the continuous churning method, and the process is as follows:

1. Raw material pre-treatment and cream preparation

• Raw milk reception and inspection: The purchased fresh milk is first subject to strict quality inspection, including fat, protein content, acidity, antibiotic residues, etc.

• Milk purification and separation: The milk passes through a centrifugal milk purifier to remove impurities, and then enters the cream separator. The separator rotates at high speed, using centrifugal force to separate full-fat milk into skimmed milk and light cream. The fat content of the light cream is usually 35%-40%.

• Cream pasteurization: The separated light cream is pumped into a plate heat exchanger for pasteurization (typically at 85-95°C for several seconds). This step aims to eliminate all pathogenic bacteria and most spoilage bacteria, ensuring product safety and extending shelf life.

• Vacuum deodorization (optional): To produce pure-flavored butter, the light cream sometimes passes through a vacuum tank, where some feed odors or other undesirable flavors are removed under reduced pressure.

• Fermentation (for fermented butter):

o If producing fermented butter (a common flavor in Europe): The pasteurized light cream is cooled to the fermentation temperature (about 20°C), and then injected into a specific lactic acid bacteria starter (such as Lactococcus lactis). It is fermented in a controlled environment for several hours, generating substances such as diacetyl, which gives butter its unique aroma and sour taste.

o If producing sweet butter: This step is skipped.

2. Physical ripening and churning

This is the key step in the formation of butter.

• Cooling and physical ripening: The pasteurized or unpasturized light cream is rapidly cooled to 4-8°C and maintained at this temperature for several hours. This process is called "physical ripening". The low temperature causes some triglycerides in the milk fat to crystallize, making the fat globules softer, preparing them for churning.

• Continuous churning: The mature cream is continuously pumped into the core equipment - the continuous butter manufacturing machine.

o First stage: Mixing and fat particle formation: In the front section of the manufacturing machine, a group of high-speed rotating churning devices vigorously churn the cream, breaking the fat globule membranes and causing the fat to aggregate into small fat particles.

o Second stage: Discharge and separation: The mixture of fat particles and liquid buttermilk is sent to an extrusion section. Through a sieve or spiral extrusion, most of the buttermilk is discharged. The discharged buttermilk can be recycled.

3. Pressing, shaping, and packaging

• Pressing: The fat particles separated from buttermilk are sent to the pressing section of the manufacturing machine. A spiral conveyor or a group of cooperating extrusion rollers repeatedly knead and squeeze the fat particles.

o Objective 1: Adjust the moisture content of butter to make it evenly distributed in the fat.

o Objective 2: Destroy the remaining fat globules to completely condense the fat into a continuous phase, forming a smooth and uniform texture.

o Objective 3: At this stage, salt (to make salted butter), pigment (such as beta-carotene), or vitamins can be added according to product requirements.

• Shaping and cutting: The pressed butter becomes a continuous, pliable strip. It is sent to the shaping machine, where it is extruded into specific shapes (such as blocks, rods), and cut into the desired weight by a high-speed steel wire knife. • Packaging: The cut butter pieces are packaged by an automated packaging machine using aluminum foil, parchment paper, or plastic film to prevent oxidation and contamination. The packaged butter is then placed in an outer box.

4. Refrigerated Storage

The packaged butter is immediately sent to the cold storage (usually ranging from -18°C to 4°C, depending on the product type and shelf life requirements), waiting for sale upon leaving the factory.

II. Core Equipment of the Butter Production Line

A complete automated butter production line mainly consists of the following equipment:

1. Cream Separator: Used to separate cream from milk.

2. Plate Heat Exchanger: Used for pasteurization of butter and subsequent cooling and heating processes.

3. Fermentation Tank (optional): With temperature control and stirring systems, used for producing fermented butter.

4. Maturation Tank: With a double-layer insulation, used for cooling and physical maturation of butter.

5. Continuous Butter Manufacturing Machine: The core of the production line. Integrates whipping, churning milk, pressing, and seasoning. Well-known brands include SPX FLOW (under Gerstenberg Schröder) and GEA, etc.

6. Milk Recirculation System: Collects and processes the separated milk.

7. Forming and Cutting Machine: Shapes and cuts the butter.

8. Automated Packaging Machine: Completes the final packaging of the product.

9. In-Place CIP Cleaning System: Crucial. Responsible for automatically cleaning and disinfecting pipes, tanks, and other equipment to ensure food hygiene and safety.

10. PLC Control System: Central control room. Monitors and adjusts the parameters (temperature, pressure, flow, speed, etc.) of the entire production process through a computer touch screen. Summary

The modern butter production line is a highly automated, closed and hygienic continuous production process. It efficiently transforms raw milk into stable, safe and hygienic butter products by precisely controlling physical and biochemical conditions. From the traditional wooden tub milk mixing to today's continuous production, technological advancements have significantly increased the yield, quality and consistency of butter.