Yogurt Pasteurizer

A yogurt pasteurizer is a yogurt processing line designed to heat raw milk or yogurt base to a specific temperature for a controlled time, in order to kill harmful microorganisms while preserving nutrients and flavor.

The yogurt pasteurizer is a specialized piece of equipment designed for pasteurizing yogurt base materials. During operation, the product is heated to 95°C and held for about 300 seconds, effectively destroying harmful microorganisms while preserving the nutritional content and unique flavor of the yogurt.

This equipment is widely used in the production of various dairy products and beverages, including:

• Set yogurt
• Stirred yogurt
• Greek yogurt
• Cheese
• Brown-colored beverages
• Fermented milk drinks

Modern yogurt pasteurizers are designed with efficiency and hygiene in mind. Common features include:

• Precise temperature control for stable pasteurization.
• Flexible capacity options suitable for small-scale dairies to large industrial production lines.
• A plate heat exchanger improves heat transfer efficiency. All plates are made of SUS316L, enhancing hygiene and corrosion resistance.
• A product-to-product heat recovery design and a five-stage plate heat exchanger effectively reduce utility energy consumption and operating costs.
• Pressure differential management is used for heat exchange between materials and hot and cold medium, and between materials, effectively minimizing the risk of product contamination and ensuring product quality.
• The temperature difference between materials and hot water during pasteurization is minimal, achieving gentle heating to maintain product flavor while effectively reducing scaling and maximizing continuous equipment operation.
• Full PLC and touchscreen control ensure easy operation.
• Data logging and alarm functions ensure strict control of substandard products.
• An independent CIP self-circulating system maximizes cleaning and energy efficiency.
• Data collection and recording can be performed using a paperless recorder or a memory card.
• CIP cleaning can be integrated into the yogurt pasteurizer or connected to an external central CIP cleaning station.
• Control can be performed locally or remotely from a central control room.

The working process of a yogurt pasteurizer involves continuously pumping raw milk or yogurt base through a pump to plate heat exchanger system, where it is gradually preheated by hot water, then brought to a high temperature of around 85–95°C and held for a precise period (commonly about 300 seconds) in a holding tube to effectively kill harmful microorganisms, after which the product is rapidly cooled to fermentation temperature (approximately 40–45°C) to ensure safety, maintain nutritional integrity, and create optimal conditions for adding starter cultures and producing high-quality yogurt.

The yogurt pasteurization process typically follows these steps:

1. Milk Feeding: Raw milk(4-5℃) is pumped into the pasteurizer.
2. Regeneration Preheating – The incoming raw milk first passes through the regeneration section, where it is preheated by exchanging heat with already pasteurized milk, saving energy and stabilizing the initial temperature.
3. Heating Section – The preheated milk then enters the heating section, where hot water or steam raises its temperature to the pasteurization range of 85–95°C.
4. Holding Section – The heated milk flows through a holding tube or chamber and is kept at the target temperature for about 300 seconds, ensuring harmful microorganisms are destroyed without damaging nutritional or sensory qualities.
5. Regeneration Cooling – After holding, the hot milk passes back through another regeneration section, transferring some of its heat to the incoming raw milk. This step improves energy efficiency and reduces cooling demand.
6. Final Cooling Section – Finally, the pasteurized milk is rapidly cooled to the fermentation temperature of 40–45°C, creating optimal conditions for inoculation with yogurt cultures.
7. Discharge: The milk is transferred to fermentation tanks for yogurt culture inoculation.

A typical yogurt pasteurizer system is made up of:

• Milk receiving tank/Balance tank: For raw milk storage before pasteurization.
• Plate-type 5-section heat exchanger: For efficient heating and cooling.
• Holding tube or tank: To maintain milk at the required pasteurization temperature for a set time.
• Control system: SIEMENS PLC and an automatic control panel to regulate temperature, time, and flow.
• Instruments: E+H Flowmeter, JUMO temperature sensor, IFM level sensor, DANFOSS inverter.
• Pumps and valves: made of SUS304 or SUS316L to ensure smooth milk circulation.
• Frame and piping: Constructed from high-grade stainless steel (usually SUS304 or SUS316L).
• Hot water system: Supplying hot water to the heat exchanger, it mainly includes Spirax Sacro steam control valves group, hot water tank, hot water pump and plate heat exchanger.