Vacuum cooking . Way of cooking by using a container subjecting it to a certain source of heat.
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- 1 Features
- 2 History
- 3 Different Applications of the Technique
- 1 Raw preservation
- 2 Traditional cooking and vacuum packaging
- 3 Vacuum cooking proper
- 4 Precautions in applying the vacuum
- 5 Fields of application of the procedure
- 6 Sources
Sous-vide (vacuum cooking) is a simple and effective method of culinary preparation by using controlled temperatures adapted to each ingredient. Invented 40 years ago in France by celebrated Chef George Pralus , this revolutionary technology, based on the immersion of vacuum-sealed bags in water at a controlled temperature, is ideal for small and large-scale food production. It is one of the most profitable high-quality culinary preparation methods for making meats, fish, vegetables, fruits, pastries, sauces and condiments for desserts and main dishes.
Blaise Pascal (1623-1662) worked from a young age on problems related to emptiness. He is owed the laws on atmospheric pressure as well as a vacuum treaty.
In the 17th century, the weight of air and the phenomenon of the rise of liquids by aspiration were known. However, the relationship between the two was ignored and the suction phenomena were explained by a supposed “horror” that nature has for emptiness. Galileo, Torricelli and Pascal then sought a scientific explanation for this phenomenon. Pascal finally found and explained the relationship between atmospheric pressure and height above sea level. In this way, the existence of emptiness was also verified. The industrial use of vacuum began with the preservation of consumer products such as coffee beans or ground coffee to preserve its aroma, milk, fruit juices, canned vegetables and fruits. Later it was used for the preservation of dishes already prepared.
In the gastronomy studies began in 1974 with Georges Pralus in his laboratory in Briennon, France. Faced with the problems of weight loss of foie gras during its cooking (between 40 and 50% of its weight), Pralus tried techniques to reduce this loss, finding that a cooking of foie gras under vacuum reached only 5% loss of weight and final quality of the product was optimal.
In 1988 Yves Sinclair and Felipe Abadía gave the first vacuum cooking talks at the food fair in Barcelona . In the 1992 edition of this fair, the Vac Club appeared, bringing together the first professionals in the field.
Different Applications of the Technique
Once the genus is cleaned, we proceed to its raw packaging for storage in the cold room . We label with the packaging and expiration date. Then it is deposited in the cold room until it is used.
Traditional cooking and vacuum packaging
When we have portioned the genre, we proceed to cook it in the traditional way.
- Rapid cooling and packaging of the product. The fabric must be quickly cooled to 10ºC in the center and 2ºC outside. Once cooled, it is packaged and labeled.
- Pack hot and then cool. Hot packaging is carried out once the goods have been cooked. Then we package and cool to 10ºC in the center of the product as quickly as possible.
The advantage of both options is to keep the traditional kitchen applying a modern and practical conservation system.
Vacuum cooking proper
It consists of cooking the fabric after it has been vacuum packed. For meat cases, it is preferable to mark them on the plate beforehand so that they have a golden color. As in the previous case, a quick cooling must be applied to the product once cooked.
Vacuum application precautions
There is a close relationship between atmospheric pressure and the temperature at which the water boils. Under normal conditions, corresponding to a pressure of 1 atmosphere, pure water boils at 100ºC. At a pressure below one atmosphere, the water will also boil at a lower temperature. Thus, at a pressure of 0.1 atmosphere, the water boils at 60ºC, and at 0.01 atmosphere, it boils at only 10ºC. Therefore, in a vacuum machine, when the pump begins to produce the vacuum inside the hood, the atmospheric pressure decreases inside it and the water contained in the food begins to boil, even when it is at room temperature inside a kitchen. When we apply a vacuum to a hot product, the pump is charged with air with water vapor, which loses efficiency. To vacuum pack hot products we must make a partial vacuum, that to avoid atmospheric pressure falling too low and to reduce the risk of boiling. The steam released by the hot food will condense as the food in the bag cools, returning to a liquid state. It is for these reasons that it is always the most appropriate thing to cool the food in a cooling cell before packing it.
Fields of application of the procedure
These products, which in themselves are long-lasting, if we vacuum-pack them, extend their expiration dates even further and obtain additional advantages. For example, there is no weight loss or drying out. Furthermore, there is no risk of acquiring strange odors because each product is in its respective container isolated from the rest. We can even save products already filleted like Serrano ham.
- Cured products (hams, sausages, marinades)
In the case of meats, vegetables, pasta, fish, salads, marinades, etc., we were able to isolate them from the outside and therefore from any contaminating agent that may cause poisoning. Likewise, we extend its shelf life in the chamber and avoid drying out and acquiring strange odors.
- Fresh or semi-prepared products
It consists of the semi-preparation of a wide range of cooked products, which will be vacuum-packed to improve their preservation. Precooked products such as cannelloni, lasagna, etc., can be packaged at any time during their preparation, even when golden.
- Traditionally cooked products
- Cooked and packaged products
Almost any product cooked in the traditional way can be packed, respecting rigorous temperature and hygiene controls. With vacuum packaging, we achieve better conservation and save effort in the manufacturing process, since we can produce them in advance and keep them preserved until use.