Industrial steam in food processing: types, applications and criteria for selecting the right system

In a food factory, temperature, humidity and hygiene are process parameters that have a direct impact on product quality and HACCP compliance. Industrial steam controls these parameters simultaneously: it heats, sterilises, humidifies and cleans. An undersized system leads to HACCP non-compliance, production line stoppages and contamination risks. The selection must be based on the specific process in each production hall.

This guide is based on Texco’s experience in designing and implementing industrial steam systems in food factories, including applications for humidification, sterilisation and integration into HACCP processes.

What is industrial steam and why does its type matter in the food industry?

Industrial steam is water in a gaseous state, produced by a generator and distributed through a network at a controlled pressure and temperature. In general industrial use, the term covers a wide range of systems, from high-pressure boilers to compact saturated steam generators. In the food industry, the classification goes further, because the type of steam determines what contact it may have with the product and what hygiene requirements it must meet.

EC Regulation 852/2004 on the hygiene of foodstuffs and the HACCP principles stipulate that any substance or agent in direct or indirect contact with food must be safe and must not constitute a source of contamination. Steam is no exception. Steam produced from untreated mains water, distributed through non-compliant pipes or containing boiler treatment additives, may contaminate the product or processing surfaces.

Therefore, in the food industry, the selection of the type of steam is a compliance requirement, not a secondary technical consideration.

Types of steam used in food factories

Dry saturated steam

Dry saturated steam is steam at the saturation temperature corresponding to the working pressure, with no liquid water droplets present. It is the standard type used in sterilisation and pasteurisation applications, where heat transfer must be precise and controlled.

Specific application: in sterilisation autoclaves for tinned or packaged products, dry saturated steam ensures that a temperature of 121°C is maintained uniformly across the entire surface of the product. If the steam contains excess moisture (wet steam), the effective temperature drops and the sterilisation cycle is not validated. Risk: non-compliant batch, withdrawn from the market.

Clean steam

Clean steam is produced from purified water (distilled or demineralised) and distributed through 316L stainless steel pipes, without any chemical additives. The EN 285 standard, used for sterilisation in autoclaves, is also frequently used as a reference in the food industry for applications with high sterility requirements.

Specific application: in production lines for sterile products or those with a high microbiological risk (dairy products, infant formula, pharmaceutical-grade food products), clean steam is the only type accepted for the sterilisation of contact surfaces. If technical steam from the mains water supply is used instead of clean steam, there is a risk of chemical residues being deposited on processing surfaces and of product contamination.

Wet steam/water vapour for humidification

Wet steam or controlled water vapour is used to regulate relative humidity in production and storage areas. It does not come into direct contact with the product, but influences product quality via the microclimate.

Practical application: in industrial bakeries or cheese maturing rooms, relative humidity must be maintained within strict ranges, typically between 70% and 95% RH. Humidity below the lower limit leads to cracking of the crust and loss of mass; humidity above the upper limit promotes condensation and the growth of mould. A controlled steam humidification system solves both problems, provided it is correctly sized for the volume and heat load of the space.

Main applications of industrial steam in food processing

Humidity control in production and storage halls

Critical parameter: relative humidity (RH), expressed as a percentage, maintained within the range specific to the process. Risks if not controlled: variations in the quality of the finished product, weight loss during storage, non-compliance with product specifications.

The right system: a steam generator with precise flow control and RH sensors that can be integrated into the building management system (BMS). Condair is a leading supplier in this category. Examples of applications:

• Bakery products (bread, frozen products, dough): maintaining RH between 70–85% to prevent surface drying and weight loss during storage.
• Dairy products (matured cheeses): controlling RH between 80–95% to prevent cracking of the rind and uneven development of beneficial moulds.
• Fresh fruit and vegetables: maintain high RH (85–95%) to reduce dehydration and extend shelf life.
• Meat and meat products: control humidity in maturing rooms to prevent excessive drying or undesirable microbiological growth.
• Packaging areas: maintain RH below 60% to prevent condensation on packaging and labelling issues.

Sterilisation of surfaces and equipment

Critical parameter: surface temperature and exposure time, validated in accordance with the HACCP protocol. Risk if uncontrolled: residual microbiological contamination, invalidation of the sterilisation process, batch recall.

The right system: a clean steam generator with controlled pressure and distribution via 316L stainless steel pipework. Jumag offers dedicated solutions for this application, with the option of certifying the steam produced. Examples of applications:

• Sterilisation of processing lines (CIP/SIP) in the dairy and beverage industry: use of a Jumag system (technical steam generator) in combination with a secondary clean steam generator to produce steam in accordance with EN 285 requirements.
• Sterilisation of contact surfaces in the production of sensitive foods (baby food, ready-to-eat products): Jumag systems with precise pressure and temperature control, integrated into automated processes.
• Sterilisation of packaging equipment and processing chambers: compact electric Jumag steam generators, suitable for localised applications or areas with gas restrictions.
• Autoclaves and batch sterilisation equipment: Jumag generators designed for constant flow, with rapid start-up and stability throughout the cycle.

Relative humidity control in packaging areas

Critical parameter: RH maintained below 60% to prevent condensation on packaging and products. Risks if uncontrolled: condensation on the packaging line, labels sticking, secondary contamination of the product.

The right system: isothermal steam humidification, with automatic control and fast response time. Integration with SCADA allows relative humidity to be correlated with line parameters. Examples of applications:

• Packaging lines for dairy products and ready-to-eat products: maintaining RH below 60% to prevent condensation on packaging and secondary contamination.
• Packaging of bakery products and snacks: humidity control to prevent packaging from sticking and product texture degradation.
• Labelling and sealing areas: preventing labels from peeling off or sealing problems caused by condensation.
• Packaging of chilled products: controlling temperature and humidity differences to prevent condensation forming on the production line.

Heat treatment of products: pasteurisation and blanching

Critical parameter: heat treatment temperature and duration, validated in accordance with the microbiological inactivation curve. Risk if uncontrolled: insufficiently heat-treated product, risk to consumer health, non-compliance with legislation.

The appropriate system: a saturated steam generator with stable pressure and constant flow rate, sized to match the thermal load of the processing equipment. Jumag covers this category with generators offering flow rates ranging from a few tens to a few hundred kilograms of steam per hour.

Examples of applications:

• Pasteurisation of milk and dairy products: maintaining a constant temperature to inactivate microorganisms.
• Blanching vegetables prior to freezing: controlled heat treatment to stabilise the product.
• Processing of ready-to-eat products: heat treatments for food safety and to extend shelf life.
• Meat processing lines: controlled heat treatment to eliminate microbiological risks.

On-site cleaning/sterilisation (CIP/SIP) in closed lines

Critical parameter: steam temperature at the point of use and cycle duration. Risk if not controlled: insufficient cleaning of the line, residual biofilm, cross-contamination between batches.

The appropriate system: a clean steam generator integrated into the CIP/SIP network, with automatic validation of temperature and pressure at each cycle. Documentation of cycles is a HACCP requirement; in practice, automatic logging is usually employed in critical applications. Examples of applications:

• Clean-in-place (CIP) in the dairy industry: sanitisation of pipes, tanks and process equipment.
• Sterilisation-in-place (SIP) in the drinks industry: sterilisation of production lines prior to a batch change.
• Cleaning in the pharmaceutical and food industries: processes with high hygiene and traceability requirements.
• Production lines for ready-to-eat food: prevention of cross-contamination between production cycles.

HACCP and hygiene requirements for steam systems

A compliant steam system in a food factory must meet several categories of requirements simultaneously: materials, the quality of the primary medium, traceability of parameters and documentation of operations.

Materials in contact with steam must be suitable for food contact. For clean steam, pipes, fittings and control equipment are made of 316L stainless steel or equivalent materials, with no porous welds and no areas where residues can accumulate. This requirement is derived from EC Regulation 1935/2004 on materials in contact with food.

The quality of the feed water is the parameter on which the quality of the steam produced depends. Water that has been chemically treated with anti-corrosion or anti-scaling additives cannot be used for the production of clean steam. Standard EN 285, used for sterilisation in autoclaves, is also frequently used as a reference in the food industry for applications with high sterility requirements.

Traceability of process parameters is an HACCP requirement for any Critical Control Point (CCP) where steam is the control agent. Temperature, pressure and flow rate must be recorded automatically and archived. A system without a log of these parameters is difficult to validate as a robust CCP; this is why automatic recording is used in practice.

The periodic inspection and maintenance of steam generators are also regulated by the Pressure Equipment Directive (2014/68/EU), which requires periodic checks and the documentation thereof.

Technical criteria for the sizing and selection of steam systems

Incorrect sizing and selection of an industrial steam system is one of the main causes of process non-conformities and high operational costs in food factories.

I. Required steam flow rate (kg/h). Correct sizing of the generator begins with calculating the thermal load of the application. For humidification, the flow rate is calculated based on the volume of the production hall, the air infiltration rate and the enthalpy difference between the initial and desired states. For sterilisation or heat treatment, the flow rate depends on the capacity of the processing equipment and the heating curve.
An undersized generator cannot maintain process parameters during peak periods; an oversized one operates in short cycles, leading to accelerated wear and inefficient consumption.

II. Working pressure. Pressure determines the temperature of saturated steam and the rate of heat transfer. For humidification, working pressures are low, below 1 bar relative. For sterilisation at 121°C, the required pressure is approximately 2 bar absolute. Systems for continuous pasteurisation can operate at higher pressures, depending on the process temperature.

III. Feed water quality. Water hardness, conductivity and organic content directly influence the generator’s service life and the quality of the steam produced. The plant must have a water treatment system appropriate to the type of application: an ion exchanger for standard applications, and reverse osmosis for pure steam. The cost of water treatment must be included in the total cost calculation for the system.

IV. Type of application. Humidification, sterilisation and thermal processing have different requirements in terms of pressure, steam quality and traceability. Before selecting a system, the plant’s applications must be inventoried and prioritised. A single system cannot optimally cover all applications if their requirements are contradictory.

V. Available space and type of installation. Compact steam generators (Jumag type) can be installed close to the point of use, reducing pressure losses in the distribution network. Centralised systems require a properly sized and thermally insulated distribution network. Available space, access for maintenance and location relative to the points of use are installation criteria that influence the total cost and operational efficiency.

VI. Integration with existing systems (BMS, SCADA). A modern factory integrates utility systems into the central management platform. A steam generator that lacks standardised communication interfaces (Modbus, BACnet, OPC-UA) cannot be integrated into SCADA and does not allow for the automatic logging of parameters. This is an HACCP compliance requirement, not merely an operational convenience.

VII. Redundancy and operational continuity. In critical applications (CIP/SIP, sterilisation, continuous processes), a shutdown of the steam system can lead to production stoppages and significant losses. In such cases, it is recommended to configure the system with redundancy (for example, two generators in parallel), so that one can take over the load in the event of a fault or maintenance.

Differences in applicability: Condair and Jumag

Condair and Jumag meet different needs in food processing. The table below highlights the main differences in applicability, not a hierarchy between the solutions.

The Texco team analyses the specific process at each factory, designs the system, carries out the installation and commissioning, and provides the technical documentation required for HACCP validation. The recommendation of a Condair or Jumag solution is based on this technical analysis, not on product availability.

What needs to be checked before purchasing?

Before making any decision to purchase an industrial steam system, the production manager or process engineer must be able to answer the following questions:

• What are the specific applications for which steam is required: humidification, sterilisation, heat treatment or CIP/SIP cleaning?
• Will the steam come into direct contact with the product or only with the processing surfaces?
• What is the maximum flow rate required (kg/h) and what are the load variations during the production shift?
• What is the quality of the available mains water (hardness, conductivity) and is there already a water treatment system in place?
• At what working pressure must the steam be supplied at the point of use?
• Is integration with a BMS or SCADA system required? Which communication protocols are supported?
• Are automatic parameter recordings required for HACCP validation?
• How much space is available for installing the generator, and are there any restrictions on the gas or electricity supply?
• What is the frequency and duration of planned maintenance shutdowns? Is redundancy required?
• What is the estimated total cost of operation (energy, water, maintenance)?

The answers to these questions determine the type of system, the installed capacity, the control configuration and the total investment cost. Without this information, any quotation remains an estimate and cannot guarantee the system’s performance in operation.

Properly sized industrial steam is a key factor in quality and compliance in food factories, not just a generic utility. The type of steam selected, the quality of the feed water, the working pressure and the ability to integrate with control systems determine whether the process operates to specification and whether the factory can pass an HACCP audit without reservations.

The Texco team analyses the factory’s specific requirements and recommends the appropriate solution. Send us the floor plan or the technical data sheet for your processing equipment, and we will provide you with a preliminary sizing estimate based on the actual needs of your application.

* Article produced in collaboration with Texco’s process engineers, who specialise in auditing thermal systems for the food industry.