Sous vide, meaning ‘under pressure’ or ‘under vacuum’ in French, refers to a style of cooking where the food product is vacuum sealed in an air-tight bag and cooked in a water bath at a precise temperature. The purpose of sous vide cooking is to cook a food item until it reaches the desired temperature throughout, without overcooking the outside of the product. This is often done over a longer period of time than conventional cooking methods such as steaming, roasting and pan frying.
When using traditional cooking methods, the food product must be heated at a higher temperature than the desired core temperature. For example, you may wish to roast a leg of lamb until it reaches 60 degrees Celsius throughout, but to do this you would need to cook the product in an oven which is heated to 180-200 degrees. This means the outside of the product, which is more exposed to the heat, will reach higher temperatures during cooking, resulting in a product which is less cooked internally than it is externally. Sous vide cooking resolves this issue as the food product is placed in a water bath which is set at a temperature equal to the desired core temperature of the product. The product cannot get any hotter than the temperature of the water it is being cooked in.
This can be especially useful when cooking a variety of foods. Vegetables and fruit can be cooked at a temperature lower than boiling point, allowing the risk of overcooking to be removed and their shape and firmness to be retained when eaten, as the cell structure is not as readily denatured at lower temperatures. At the same time, when meat is cooked using sous vide, the collagen between the muscle fibre is broken down without the fibres becoming tough from overcooking. This allows for a more tender piece of meat which has not lost its moisture.
Sous vide is not just useful for cooking. It is an invaluable tool when reheating foods, especially for catering purposed. Foods such as curries and stews can be cooked in advance, chilled, then placed in vacuum bags for storage and reheating. A bag of food reheated to the desired serving temperature using sous vide will not lose any moisture in the reheating process and will not cook any further. This also means that the food can be held in the water bath until ready for service, removing issues with timing when large quantities of meals need to be served.
Despite the many advantages of sous vide cooking, there are some minor limitations. Steak and other meat will not develop the brown ‘crust’ which is often desired and will need to be sealed quickly in a hot pan after cooking in the water bath in order to achieve this.
When setting up your kitchen for sous vide cooking, you will require some new equipment. You can purchase a free standing bench top unit such as one from the Roner series which consists of a thermostat and bowl in the same device. These units, which come in two sizes, provide the water circulation and temperature stability needed for sous vide cooking and are made from stainless steel. Alternatively, there are a variety of portable thermal circulators available which provide the same temperature accuracy, but are able to be used with any heat resistant pot or container (size subject to the machines limitations). If you are interested in sous vide cooking, need any advice or information, or wish to purchase the necessary equipment for your kitchen, please contact us at Rely Culinary Technology.
Written by Kathryn Hill