Implementing Sous-vide Technologies in a Canteen, Restaurant or Cafe: A Strategic Necessity
- Fedor Sokirianskiy
- 14 hours ago
- 8 min read
Implementing innovative technologies in a canteen or cafe is not merely a matter of following fashion or an industry trend. It is, perhaps, the only chance to maintain competitiveness and effectively manage the direct cost of goods sold under modern market conditions.
The implementation of innovation is not as difficult or expensive as it might seem, provided you clearly understand your production goals and objectives.
For example, preserving the mass of meat products can be achieved through several methods: injection into the vein and mass, mechanical and vacuum tumbling in a massager. We can also preserve product weight during high-speed defrosting using steam, high-frequency, or even radiation-based thawing principles. Or, we can freeze the product at very low temperatures down to minus 75 degrees Celsius. In all these cases, we either increase the product mass or reduce losses during its defrosting. Furthermore, there are other, more "gentle" methods for preserving product mass during heat treatment. One of them is sous-vide technology.
It is often considered a technology of high-end restaurant cuisine. However, low-temperature cooking finds its application in the corporate dining segment, in fast food, and in the prep kitchens of large restaurants.
A brief technological description of the low-temperature cooking process is as follows. Meat or a meat by-product is placed in a vacuum bag made from composite polymer materials with high barrier properties. High barrier properties refer to gas impermeability, meaning they prevent contaminated atmospheric gases from penetrating the packaging. Technologists should pay attention to the composite composition of vacuum bags and the reliability of their manufacturer, as it is precisely the barrier packaging that ensures maximum bacteriostatic effect on the product surface, thereby increasing its shelf life.
Often, manufacturers use laminated materials, where "barrier" properties are achieved by adhesively bonding a non-barrier, cheap polymer to a thin barrier film. Seeking to reduce costs, the manufacturer does not provide the necessary high-barrier properties. A meat product packaged in such cheap packaging cannot ensure a shelf life of more than 5-7 days. High-barrier films, along with absorbent pads and oxygen absorbers, can extend the shelf life of properly aged chilled red meat to up to 120 days at a temperature of plus 2 to plus 6 degrees Celsius.
The bag predominantly consists of highly transparent, multifunctional LLDPE material. This material has excellent heat-shrink properties and good tear and puncture resistance. Therefore, during vacuum sealing, the film tightly envelops the product. This effect contributes both to increased thermal conductivity of the packaging and helps retain moisture inside the product, ensuring cooking "in its own juices." Tear resistance allows vacuum sealing of "problematic" products like pork ribs without compromising the packaging integrity.
During vacuum sealing, the bag with the product is placed inside the chamber of a vacuum packaging machine, which, using a vacuum pump, creates a pressure differential and evacuates air from the package. The bag is often pre-inflated with an air nozzle to smooth its edges and the muscle fibers, ensuring minimal residual oxygen inside the package after air evacuation. The degree of vacuum is regulated by the volume of air evacuated. A delicate product like pate can be vacuum-sealed in a gentle mode to avoid damaging its texture. It is worth considering that the residual oxygen content in the package in this mode will be higher than with "hard" vacuum sealing, and the shelf life, accordingly, shorter. After vacuum sealing, brief scalding of the package in boiling water for 1-2 seconds can be useful for additional sealing of the seam around the product. This is done to ensure the tightest possible fit of the bag to the product, less juice leakage, and to push any liquid that has leaked from the product back towards it. Immediately after scalding, the bag is placed in an ice-water bath at 0.5 to 1 degree Celsius for 1 to 2 minutes. This is necessary to ensure rapid cooling and reliable crystallization of the weld seam. It should be noted that most cheap laminated vacuum bags begin to delaminate during scalding at temperatures close to sterilization. The solvent-based adhesive used to bond the barrier and non-barrier layers cannot withstand temperatures of 99 degrees Celsius and begins to melt, delaminating the film. We advise technologists to use high-quality bags made from five to seven-layer barrier film produced by blown extrusion, not lamination.
After the bag seam has cooled in the ice bath, we place it in a container for low-temperature cooking. This container can be a stovetop kettle or a 1/1 or 2/1 polycarbonate or stainless steel gastronorm container. A low-temperature circulator is attached to the wall of the container using a bracket with a screw clamp. The distance from the bottom of the container to the lower edge of the circulator's protective housing should not be less than 4 cm. Hot water at a temperature not lower than 50 degrees Celsius is poured into the container. This water temperature will allow the circulator to start working faster and use less electricity to reach its operating mode.
Standard "restaurant" models confidently work with tanks and containers up to 30 liters. If you plan serial production of semi-finished products, it makes sense to work with more powerful circulators. The cost of such an apparatus ranges from 1000 USD-1500 USD.
What does low-temperature cooking in vacuum bags provide? The product acquires unique taste properties due to cooking in its own juices. The meat product gains incredible tenderness because almost all connective fatty tissue remains dormant, protein coagulation proceeds differently, muscle fibers hardly contract, and product dehydration is minimal. The nutritional composition of the product retains many more vitamins and valuable amino acids compared to a product treated at pasteurization and sterilization temperatures.
Sous-vide technology is used in both high gastronomy and corporate catering. For a production volume of 100 to 1000 kg per day, it is advisable to use up to 10 small apparatuses. For production of over a ton per day, it makes sense to use specialized equipment like cooking tanks and waterjet chillers. We will discuss this technology, known as CapKold, in a separate article.
It should be fairly noted that low-temperature cooking is also possible in a combi-oven, both in a water container with a temperature probe and on a rack. The difference in cooking lies in two aspects. First, the combi-oven's fan will provide intensive airflow to the bag, for example with a chicken breast, only from the side where it is installed in the oven chamber. The opposite side of the product will receive less thermal energy. As a result, the product will be overcooked on one side and undercooked on the other. During subsequent browning on a grill or in a convection oven, the product will heat unevenly and the crust will be uneven. Second, the energy consumption for low-temperature cooking in a combi-oven exceeds that of cooking in a water thermostat by 8 times.
Sous-vide technology significantly expands a technologist's arsenal in the field of corporate catering.
Regeneration of Meat Dishes After Sous-Vide Cooking
It is important to understand that in corporate catering, sous-vide technology is used more as a pre-preparation technology rather than final cooking. After low-temperature cooking in a vacuum bag, we immerse it in an ice bath to cool it as quickly as possible and prevent the resumption of microbiological growth. Cooling in ice water is the fastest way to reduce temperature. After such cooling, a product like lamb loin, bone-in pork loin, or chicken breast can be stored under medium-temperature refrigeration for up to 25 days.
How does the regeneration of a product after sous-vide cooking occur? First, it is important to understand that the internal temperature of the product is plus 2 to plus 4 degrees Celsius, and in this state, it cannot be reheated or fried directly. If a cold product is cooked further, the juices will simply flow onto the plate when the piece is cut. The meat must be heated, preferably in a stovetop kettle or in a large bath with the same sous-vide circulator set to plus 60-65 degrees Celsius.
After the product reaches the desired temperature, it can be removed, the bag cut open, and the product prepared for final cooking. The remaining juices in the bag are advisable to use for sauce preparation.
The best result for finishing a product after sous-vide is achieved by grilling over charcoal or searing on a plancha. Sous-vide is ideal for preparing challenging beef cuts, like chuck, which requires 10-12 hours of cooking to fully tenderize. Such an effect is usually only possible in a pressure cooker. But unlike pressure cooking, where all juices go into the broth and the meat becomes completely dehydrated, sous-vide often has the opposite effect, and the product not only doesn't lose mass but even gains a couple of percent in weight. This effect is observed during the long cooking of beef, chicken, and tiger prawns.
Recommended equipment for finishing products cooked sous-vide includes wood-fired, gas, and electric grills, contact grills, salamanders, fryers after breading, pan-frying in oil, and baking.
Recommended products for sous-vide cooking in corporate catering include tiger prawns, salmon and salmonids, all beef cuts including alternative cuts, pork neck and boneless/bone-in loin, pork ribs, chicken breast and wings, liver, kidneys, gizzards, turkey breast and thigh, mushrooms, and minced meat.
Pasteurization in Sous-Vide
Pasteurization technology has been known to the food industry for over two hundred years. It has been applied in corporate catering relatively recently. The essence of the pasteurization process is simple: any food product, after being hermetically packaged and thermally processed at a temperature from 80-85 degrees Celsius for a duration from 1 minute to 10 minutes, can be stored under medium-temperature refrigeration for up to 40-50 days. The product must be cooled to plus 2 to plus 4 degrees Celsius within no more than 90 minutes.
The shelf life increases because one of the three main groups of aerobic bacteria that survive up to 75 degrees Celsius, thermophiles, partially die and partially go into a dormant state at pasteurization temperature. Thus, pasteurization temperature has a bacteriostatic effect on the product.
In practice, the pasteurization process in a canteen or commissary kitchen proceeds as follows: the finished soup or stew is cooled to plus 40-50 degrees Celsius for safe packaging. The product is then portioned into vacuum bags and sealed. The bags are placed in a sous-vide water bath, held for 10 minutes, and then placed in an ice bath for 30-40 minutes. After cooling, the product can be stored for up to 30 days at plus 2 to plus 4 degrees Celsius.
Attention: In public catering, shelf life is determined by SanPiN regulations. Shelf lives exceeding 24 hours must be confirmed by Technical Specifications, Technological Instructions, and results of microbiological analyses from an accredited laboratory.
Essential Guidelines for Working with Food Products
All products have primary contamination.
Your task is to suppress this contamination using physical and chemical methods, culinary techniques, and equipment.
Products spoil in environments favorable to microorganisms, which thrive when it's moist, warm but not hot, non-acidic, and oxygenated.
We can deprive them of these conditions by creating an acidic environment, deep freezing, an airless space, or high-temperature treatment.
Products spoil due to excessive temperature, humidity, atmospheric air, and enzyme activity.
The main enemy of products is oxygen, which degrades nutritional value, texture, and taste. Protect the product with moisture-proof and hermetic packaging.
A freezer is not a panacea, as it can cause freezer burn.
Vacuum sealing solves most product storage problems by removing up to 90% of the air.
Vacuuming reduces oxygen content inside the package to about 2-3%.
Most bacteria stop growing at 5% oxygen inside a package.
There are three main groups of microorganisms: molds, yeasts, and bacteria.
Molds do not grow at low oxygen levels and in the absence of moisture.
Yeasts grow very quickly in the presence of temperature above 30°C, sugar, and moisture. Complete freezing is required to stop them.
Bacteria are very hardy and can grow with or without oxygen.
Clostridium botulinum can grow without air, in a vacuum, between 24°C and 58°C. Its growth can be inhibited by acid, complete absence of oxygen, and high temperatures.
Vacuum does not destroy bacteria; it only inhibits their growth.
Do not vacuum products that have been sitting in the workshop for more than 30 minutes. Vacuum will only worsen their condition. Adhere to the concept of continuous cold chain.
Take a product from the refrigerator, cut off the portion needed for processing, and put the rest back immediately.
Vacuum sealing, pasteurization, and defrosting after shock freezing require ideal sanitary and hygienic conditions.
There are ethylene-producing products that should not be packaged without peeling—all citrus fruits, bananas, kiwis, apples, peaches, and others.
If representatives of Rospotrebnadzor request permits for a seven-day chilled vacuum-packed steak, their demands are legitimate. You are required to have Technical Specifications and Technological Instructions for the extended shelf life, even if you are a cafe or restaurant and not a commissary kitchen.
Comments