How to cook sous vide safely in your food business.

This article has been written by Pilla Founder, Liam Jones, click to email Liam directly, he reads every email.

Sous vide is French for ‘under vacuum’ and describes a method of cooking in vacuum sealed plastic pouches at low temperatures for long periods. Sous vide cooking differs from conventional cooking methods as the raw food is vacuum sealed in a plastic bag and the food is cooked using more precise temperature control.

Benefits of a sous vide cook

The sous vide method of cooking is said to maintain the integrity of the ingredients and therefore should produce foods with enhanced flavours. A sous vide cooker gives the chef more control over the cooking of a dish. Sous vide techniques are often used in fine dining restaurants and more professional kitchens because it offers a more luxury finish to the dish.

Steak cooked via the sous vide method is more consistent than traditionally cooked steak and the same can be said for any other sous vide recipes.

Risks with sous vide cooking

There are additional risks through the whole sous vide process to be aware of. The low temperature of sous vide cookers as well as the unique handling of the food means that additional steps need to be taken with this cooking method. If you want to cook sous vide, follow the cooking technique in this article to ensure food safety.

Food Borne Pathogens associated with sous vide cooking

Clostridium botulinum - The anaerobic (absence of oxygen) conditions with sous vide cooking together with the relatively low cooking temperatures provides an opportunity in which Clostridium botulinum can survive and grow producing a toxin which is not destroyed by heat. Botulism is a serious illness that can lead to paralysis and death.

• •Sources: Soil, vegetables, intestinal tracts of fish and mammals
• •Example food vehicles: Low acid processed foods, bottled vegetables, flavoured oils and vacuum-packed products.
• •Growth temperatures: 3°C to 50°C-pH = 4.6 to 9
• •Controls: low acid foods pH 4.5 or lower, strict heat treatment, e.g., botulinum cook, strict attention to the shelf life of chilled vacuum-packed foods: 10 days maximum without additional controls

Clostridium perfringens - Spores can survive the normal cooking process and multiplication can occur if the temperature control is inadequate. Toxins form within 6 hours; this is the maximum time food can be cooked in the danger temperature of 10°C to 52°C without further controls.

• •Sources: Soil, intestinal tracts of humans and animals, raw meat, dust and insects.
• •Example food vehicles: Beef (especially rolled joints), turkey, pork, chicken, cooked mince, gravy, soup, stews and sauces.-Growth temperatures: 0°C to 52°C-pH = 5 to 8.9
• •Controls: Food should be consumed immediately after cooking, store food above 63°C, rapid cooling within 1.5 hours and thorough reheating of foods.
• •pH:minimum 4.3Controls:use food within date codes, refrigerate between 0 and 5°C, thorough reheating of cook chill products, avoid cross contamination and wash fruit and vegetables including salads.

Salmonella – can be killed by heating to a core temperature of 70°C for 2 minutes or equivalent.

• •Source: Water, soil, sewage, intestinal tracts of animals especially poultry and swine, raw meat, eggs and milk.
• •Example food vehicle: Beef, turkey, pork, poultry, eggs, cheese, salad vegetables and raw milk.
• •Growth temperature: 7°C to 47°C-pH: 3.8 to 9-Controls: Avoid use of raw eggs which are not fully cooked, thorough cooking of poultry, temperature control.

E coli 0157 – the infection is caused by a low effective dose.

• •Source: Intestinal tract of humans and animals, sewage and water.
• •Example food vehicle: Raw or rare meats and poultry, raw milk and milk products, unprocessed cheese, undercooked burgers, mince, cooked meats and seafood.
• •Controls: Thorough cooking, careful handling to avoid cross-contamination.

Process for cooking sous vide safely

• •Identifying any hazards that must be prevented, eliminated, or reduced to acceptable levels 
• •Identifying control points and safe limits within your safe method steps, such as time and temperature controls
• •Establishing effective monitoring procedures
• •Establish corrective actions when monitoring indicates a problem
• •Document safe working methods which should include staff training.
• •Specialist equipment should be used including water bath, pouches and sous vide thermometer. Water bath must have a cut off if the water runs dry
• •Use high quality fresh ingredients from a reputable supplier.

Vacuum packer

• •Food quality packaging to be used 
• •Follow the instructions for the food sealing system
• •Avoid air bubbles which can cause uneven cooking
• •Preheat the water bath to the temperature before submerging sealed bags
• •A separate vacuum packer for raw foods and cooked foods is required
• •It is recommended vacuum packets of raw food are used within 2 days
• •Label vacuum packed pouches with a date and Storage ensure a secure seal on each pouch.

Temperature guide for sous vide cooker

For products that need to be cooked to destroy Listeria of monocytogenes, Salmonella, E coli 0157 or any other vegetative pathogen, restaurants will need to prove that the cooking process will enable food to reach a core temperature for the recommended time during cooking to ensure the food is safe to consume.

The temperatures are:

• •60°C for 45 minutes
• •65°C for 10 minutes 
• •70°C for 2 minutes 
• •75°C for 30 seconds 
• •80°C for 6 secondsIf high risk dishes are not going to reach a minimum core temperature of 60°C for 45 minutes or equivalent, you must verify your safe methods.

Process for cooking sous vide in a sous vide bath

• •Calibrate equipment including water baths and probes regularly. Time/temperature/size of product combinations for each product must be documented. Variation in weights is critical to time temperature control 
• •Monitor to ensure correct time temperatures are carried out of both the water bath and the core temperature
• •The storage of food under vacuum allows the potential for Clostridium bacteria to grow some of which produce toxins that may not be de-natured by pan searing before service and can have very severe effects
• •Overloading of pouches in the water bath can lead to uneven cooking. Food must be completely submerged
• •Set the water bath 2.5°C above the target temperature of the food to achieve the correct core temperature-Carefully remove the bags at the end of cooking and serve immediately or cool quickly. Chill food to under 3°C within 90 minutes to slow down the growth of food borne pathogens.
• •Change the water in the water bath frequently.
• •Food that has been vacuum packed and subjected to sous vide cooking/chill should be used within 10 days of packaging