Sausage cold storage: temperature standards and design solutions

Cold storage for sausages is an industrial refrigeration system designed specifically to hold temperatures from 0°C down to −25°C (−13°F) with humidity controlled at 83–85%, preserving sausage quality throughout the storage cycle. Sausage is a processed meat product that is highly sensitive to temperature. A variation of just 2°C between zones in the store is enough to cause localised spoilage, directly affecting food safety and production costs.

This article is a complete technical guide to sausage cold storage: classifying sausage by its thermal characteristics, the temperature and humidity storage standards, the construction of a dedicated cold store (PU insulated panels, R404A refrigeration, insulated doors), the 5-step design and installation process, and the criteria for choosing a contractor. 

Tan Long — with more than 20 years in industrial refrigeration and a partner to C.P. Vietnam, Lotte F&G and Kyokuyo Vina Foods — shares practical experience from completed projects, so readers have a basis for assessing and supervising the quality of a cold store for

Correct refrigerated storage for each type of sausage

Sausage is a processed meat product, sensitive to temperature and humidity. Depending on the type (raw, cooked or frozen), storage temperatures range from 0°C to −25°C (32°F to −13°F). Understanding the thermal characteristics of each type is the basis for designing the right sausage cold store.

Why does sausage need refrigerating even though it is already processed? The danger zone of 4–60°C (39–140°F) is the range in which bacteria double every 20 minutes. Sausage left at room temperature for more than 2 hours is no longer safe to eat. The table below summarises the storage temperature and duration for each type of sausage.

Raw sausage: 0°C – 4°C (32°F – 39°F)

Raw sausage is made from uncooked meat that has had no heat treatment. It needs continuous refrigeration between 0–4°C (32–39°F) and use within 3–5 days. Where a producer needs to store it longer, raw sausage must be frozen to −18°C (0°F) within 2 hours of production. Typical products include Bratwurst (Germany), salsiccia (Italy) and Vietnamese-style fresh sausage.

Cooked and smoked sausage: 0°C – 5°C (32°F – 41°F)

Cooked sausage has been heat-treated or smoked during production. It stores longer than raw sausage — 1 to 2 months at 0–5°C (32–41°F). Typical products include frankfurters, Wieners and peninsula-style smoked sausage. Once opened, cooked sausage should be used within 3–5 days.

Frozen sausage and blast freezing: −18°C to −25°C (0°F to −13°F)

Frozen sausage needs holding at ≤−18°C (0°F) to maintain quality for 4 to 12 months. Vacuum packaging extends that by a further 30–50% over ordinary packaging. For industrial producers, a −25°C (−13°F) freezer store is the most common solution for finished sausage awaiting distribution. To maintain quality for each type, the cold store needs its own separate air circulation.

Temperature, humidity and storage condition standards for sausage in a cold store

Storing sausage in a cold store means controlling 3 factors at once: temperature (−25°C to 5°C by type), humidity (83–85%) and even air circulation throughout the store. A temperature variation of ≥2°C between zones causes localised spoilage and stock losses.

83–85% is the optimum humidity for sausage. Below 80%, sausage loses moisture, loses weight and the surface deforms. Above 90%, the environment allows mould to develop, causing off odours and affecting the product's appearance. The evaporator fans need to run continuously to distribute the cold air evenly and avoid local “hot spots”.

Exception: Dry fermented sausage (salami, pepperoni) has different requirements. It is stored at 12–15°C (54–59°F) at 70–75% humidity to maintain the fermentation. A cold store for fermented sausage needs its own design and must not be combined with a freezer store.

To achieve and maintain these standards, a sausage cold store needs to be designed with the right construction and equipment.

Sausage cold store construction: insulated panels, refrigeration system and doors

Cold storage for sausage comprises 3 main groups of components: the insulated panels, the refrigeration system (compressor + evaporator + refrigerant), and the doors together with the temperature monitoring system. Component quality determines 60–70% of the store's performance and service life.

PU and EPS insulated panels – thickness, thermal conductivity and application in a sausage store compared

The insulated panel is the “shell” of a cold store. The two common types are PU (polyurethane) and EPS (expanded polystyrene). For a −18°C sausage freezer store, PU panel 100–150 mm (4–6 inches) thick is the best choice.

Tân Long sử dụng panel PU mật độ 40–42 kg/m³, hệ số cách nhiệt 0,022 W/mK. Panel được chỉ định theo dải nhiệt độ thiết kế của từng kho và nghiệm thu đầu vào trước khi lắp, thay vì lắp theo loại có sẵn.

The refrigeration system: compressors, evaporators and the right refrigerant for a sausage store

Which refrigerant suits a sausage store? R404A and R507 are the two common refrigerants for small to medium sausage cold stores. NH3 (ammonia) applies only to industrial stores over 100 m³ (3,531 ft³), because of its toxicity if it leaks and the strict operating requirements.

Screw compressors suit high-capacity stores. Piston compressors suit small stores under 100 m³. An evaporator for a sausage freezer store needs defrost heaters, because the low temperature ices up the fins quickly. The defrost cycle is normally set to 4–6 times a day, 15–20 minutes each time.

Cold store doors and automatic temperature monitoring

Cold store doors come in 3 main types: insulated sliding doors for industrial stores (with forklift access), hinged doors for small stores, and high-speed doors for high-frequency loading areas. Tân Long's T-Light cold store door is designed with heat-resistant gaskets and anti-condensation heaters, suiting sausage freezer stores.

An automatic temperature logger records the temperature every 4 hours and alarms when it deviates by more than ±1°C. This is mandatory for a sausage producer to achieve HACCP and ISO 22000 certification.

Designing and installing a sausage cold store: the 5 key steps

Designing and installing a sausage cold store involves 5 steps: survey the requirement, technical design, install the components, commission and calibrate, and inspect and hand over. The order of work determines the store's operating performance and service life.

Step 1 – survey the storage requirement and calculate the refrigeration capacity

The survey establishes 4 input parameters: the volume of sausage to be stored (tonnes a day or m³), the type of sausage (fresh or frozen), the installation space, and the available power supply. The refrigeration capacity is calculated from the weight of goods, the ambient temperature (normally 32–36°C / 90–97°F in Vietnam) and the frequency of movements in and out. The basic formula: heat load = weight of goods × specific heat capacity × temperature difference.

Step 2 – technical design and construction drawings

The construction drawings show the store layout, the evaporator positions, the refrigerant pipework, the condensate drainage and the door gasket heaters. Panel thickness is chosen by operating temperature: 100 mm (4 inches) for a 0–5°C sausage chill room and 150 mm (6 inches) for a −18°C freezer store. The floor needs ventilation sleepers of 300×200 mm (12×8 inches) at 400–500 mm (16–20 inch) centres.

Step 3 – install the panels, doors and refrigeration system

Panel installation order: floor → walls → ceiling. Wall panels lock together with cam-locks, with joints ≤1 mm sealed with heat-resistant silicone. The door is fitted on an aluminium or stainless frame with rounded trims to prevent condensation.

Installing the refrigeration system demands high accuracy. The compressor sits on anti-vibration mounts, with ACR-grade copper pipe connections. Pipework is brazed under a nitrogen purge to prevent internal oxidation. After brazing, the system is evacuated to ≤500 microns and held for 4 hours — if the pressure rises, there is still a leak and the joints need rechecking.

The Tân Long team uses a double evacuation procedure on every project — first pulling down to 500 microns, breaking the vacuum with nitrogen, then pulling down again to ≤500 microns and holding for 4 hours. This removes moisture and contaminants from the pipework completely, extending compressor life and reducing the risk of a stuck expansion valve.

Step 4 – commissioning and calibrating temperature and humidity

Once the R404A charge is in to the design weight, the system runs continuously for 4–8 hours to reach set-point. The technician measures the temperature at several points in the store, checking the variation is ≤2°C. At the same time the evaporator defrost cycle is calibrated — normally 4–6 times a day, 15–20 minutes each. The compressor current must be stable and not exceed 105% of its rated capacity.

Step 5 – inspection, handover and operator training

The handover inspection checks 3 main criteria: temperature variation ≤2°C between zones, humidity variation ≤5%, and stable compressor current. The handover documentation includes the as-built drawings, the equipment warranty book, and the operating and maintenance instructions. A store that passes inspection is issued with an operating certificate and the warranty period begins.

Important points when operating and maintaining a sausage cold store

Operating a sausage cold store requires routine maintenance to sustain performance and equipment life. The usual cycle: monthly for the evaporators (defrost, clean the fins), every 3–6 months for the compressor (measure current, check refrigerant), and annually for the whole system. Arrange stock on the FIFO (first in, first out) principle so sausage always leaves before its use-by date. Record the temperature every 4 hours with an automatic logger.

Choosing a contractor that offers maintenance after installation reduces long-term operating risk. A professional contractor will have a scheduled maintenance contract, a 24/7 fault hotline and spare parts in stock.

Criteria for choosing a sausage cold store contractor

Choose a cold store contractor on 5 criteria: experience with processed food projects, equipment manufacturing capability, certification (HACCP/ISO), warranty terms, and after-installation maintenance service.

Tân Long is one of the few companies in Vietnam that both designs and builds and manufactures its own equipment, at its plant in Đức Hòa 1 Industrial Park, Tây Ninh. Its partners include C.P. Vietnam, Lotte F&G and Kyokuyo Vina Foods — food processing plants with strict food safety requirements. A list of featured projects can be seen on Tân Long's projects page.

Price list of cold storage for sausages in Tan Long 

Cold storage with positive temperature (2 to 10 degrees Celsius) at Tan Long 

Cold storage with negative temperature (-10 to -20 degrees Celsius) at Tan Long 

Take control of sausage storage quality right from the cold store design stage

Temperature and humidity are vital to sausage quality. The 5-step process from survey to handover ensures the store operates at its design capacity from day one. Choosing a contractor with real experience of processed food plants is how you reduce long-term operating risk.

Contact Tân Long for design advice on a cold storage sausage suited to your scale of production. Hotline: (+84) 933 357 058.

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