Sous-Vide Technology – A Revolution in Cooking. Laboratory Work Summary
- Jun 20
- 10 min read
We are proud to share with you some of our laboratory experiments held with our Russian friends - outstanding chefs from Saint-Petersburg Ilya Lazerson and Dmitriy Blinov, 2 stars Michelin chef.
We have reached realyy good results with perfect egg in sous-vide, shaurma turkey and.... suprise: fresh strawberry.
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A Textbook for Managers and Chefs in the Hospitality Industry
Author: Sokiryanskii Fedor
The unique Sous-vide technology was invented in France by Chef Georges Pralus, who first cooked foie gras in a vacuum bag, discovering that the liver had a more delicate flavor and better texture after sous-vide processing.
Technology Description
As is known, vacuum packing and cooking, for example in a combi-steamer, can reduce product weight loss (e.g., meat) from 20–35% down to 5–7%. This technology has long been used in restaurant cooking.
When pressure is reduced, water boils (producing steam) at just below 100 °C. Food contains certain beneficial but heat-labile components (i.e., heat-sensitive), such as vitamins and some proteins. Vacuum packaging of products in polymer bags greatly helps preserve all the beneficial properties of the product. Vacuuming removes oxygen from the package, which could otherwise cause oxidation reactions (changes in molecular structure) or denaturation (loss of biological value of proteins) of many food components.
Consequently, vacuum cooking allows many micronutrients in the product to remain unchanged both nutritionally (vitamins, proteins, carbohydrates, and fats) and organoleptically (taste and aroma). The vacuum method protects food from organoleptic changes that may occur during traditional heat treatment and exposure to high temperatures, which primarily affect the color, smell, taste, weight, and digestibility of the food product.
In addition, this practice ensures greater cooking uniformity and better hygiene safety during product storage.
Vacuum cooking is applicable to both fresh products and semi-finished products placed in packaging that prevents the loss of moisture, juices, and volatile substances during the cooking process.
Control and precision of the temperature kinetic regime become key factors in choosing equipment, which is the foundation of success for any food service establishment.
The minimum temperature for cooking in a vacuum bag is +65 °C, while the maximum temperature is +93/95 °C.
Special attention should be paid to the texture and thickness of the product being cooked. Increasing the thickness of the product requires cooking at lower temperatures; therefore, a product thickness exceeding 5 cm will require longer cooking times. In classic technical literature, a thickness limit of 5 cm is recognized as the maximum recommended cut thickness for rapid cooking.
Advantages of Sous-vide Cooking:
- Preservation of the product's aromas and juices;
- Reduction in weight loss by 15–35%;
- Energy savings of 20–28%;
- Prevention of shrinkage and dehydration of the product;
- Prevention of lipid oxidation in the product and, consequently, prevention of rancidity;
- Longer shelf life of the product after vacuum cooking;
- Saving on spices by 3–40%, since the concentration of seasonings and fats is maintained due to the presence of the packaging;
- Increased cooking speed while maintaining heat input;
Any food product, depending on its ingredients and molecular structure, undergoes stages of morphological changes depending on the processing temperature and cooking duration.
Whatever heat treatment method is used, cooking temperatures range from 65 °C to 95 °C (at least at geographic latitudes at sea level). The only exceptions are vacuum cooking and retort-pouch autoclaving.
An important parameter that should be kept under control whenever possible is the temperature delta, i.e., the accuracy and targeting of heat transfer. Temperature fluctuations during cooking should not exceed 2 °C.
Sous-vide has the following biokinetic temperature treatment zones:
- Guaranteed conditional pasteurization zone: > 63 °C +
- Start of pasteurization zone: 60 °C – 63 °C
- Possible cooking zone: 55 °C – 60 °C
- Danger zone: 50 °C – 55 °C
- Extremely dangerous zone: 20 °C – 50 °C
- Danger zone: 10 °C – 20 °C
- Possible cooking zone: 3 °C – 10 °C
Since temperature and its precise gradient fluctuation are of utmost importance when cooking using this technology, chefs at all three-Michelin-star restaurants without exception use thermal circulators.
Specifications of a Standard Sous-vide Thermal Circulator:
- Temperature range: +20...+300 °C
- Temperature control: Touch-button
- Thermostat accuracy: ±0.01 °C
- Heating step: 0.01 °C
- Built-in timer: Yes
- Heater power: 3000 W
- Pump drive: 1.1 Bar, 22–26 L/min
- Safety functions: Automatic stop of rotation and heating in case of overheating, stop when liquid level in the container is insufficient
- Additional options: Data exchange with PC, temperature sensor for obtaining dish core temperature information
Practical Examples of Product Processing Using Sous-Vide Technology
Experiment 1. Chicken Breast in Sous-Vide
Working with chicken using sous-vide technology probably yielded the most outstanding results. First, in terms of weight loss, and second, in terms of taste.
We cooked four samples of chicken breast – on the first day of the experiment, marinated in BBQ sauce with a mixture of three peppers and garlic powder, and without additives on the second day. We also cooked chicken this way during our on-site master classes in Vladivostok and Samara.
The weight of the samples (second day) was: 136 g, 140 g, 137 g, and 119 g respectively.
We processed the chicken for 1 hour 9 minutes to 1 hour 25 minutes at a temperature of +60.5 °C. The thickness of the pieces was approximately 25 mm.
This experiment was required to obtain information on weight loss during the maximum possible sous-vide processing time, achieving a well-done degree of doneness.
The weight of the finished product was respectively 120 g, 125 g, 124 g, and 111 g (11.7%, 10.7%, 9.4%, 6.7%). Notably, with increasing cooking temperature, weight loss was smaller. This is explained by the fact that during longer processing, the gelling of lipids accelerates, i.e., moisture gelatinization in the product increases.
Classic temperatures and cooking times are presented in the table.
| Thickness mm | 136°F (57.5°C) | 141°F (60.5°C) | 146°F (63.5°C) | 151°F (66°C) |
|--------------|----------------|----------------|----------------|--------------|
| 5 | 1:40 | 31 | 10 | 5 |
| 10 | 1:45 | 36 | 15 | 10 |
| 15 | 1:53 | 44 | 23 | 17 |
| 20 | 2:04 | 55 | 34 | 26 |
| 25 | 2:18 | 1:09 | 46 | 38 |
| 30 | 2:35 | 1:25 | 1:01 | 51 |
| 35 | 2:55 | 1:44 | 1:17 | 1:05 |
| 40 | 3:18 | 2:05 | 1:36 | 1:22 |
| 45 | 3:44 | 2:28 | 1:56 | 1:40 |
| 50 | 4:12 | 2:54 | 2:17 | 1:59 |
| 55 | 4:43 | 3:20 | 2:41 | 2:20 |
| 60 | 5:16 | 3:49 | 3:06 | 2:43 |
| 65 | 5:52 | 4:20 | 3:32 | 3:07 |
| 70 | 6:29 | 4:52 | 4:01 | 3:33 |
You can view the results of the experiment in the video at:
The mushrooms were cooked using a slightly different scenario. We cooked fresh champignons at 65.5 °C for 50 minutes and achieved a weight loss of only 6%.
At the end of the experiment, we used the mushrooms, chicken breast, and al dente bell peppers to make pizza. The results can be seen in the slideshow: http://www.slideshare.net/pitportal/chicken-breast-sous-vide?from=ss_embed
Experiment 2. King Prawns
King prawns did not give us high hopes for achieving brilliant results with sous-vide. Nevertheless, despite our chef's skepticism, I insisted on cooking them. We worked with frozen black tiger prawns at a temperature of 60.5 °C for 10, 12, 15, 17, and 20 minutes. Weight loss ranged from 29–33%. The prawns, likethe chicken after sous-vide, ended up in the pizza, which we happily ate after the experiment.
The prawns were much more tender than usual, and during cooking and rapid cooling on ice, bright red stripes appeared on them—much brighter than with conventional processing. Unfortunately, the weight loss was far from as small as we had expected. We concluded that aside from minor flavor changes, the product did not show any particularly outstanding results.
Experiment 3. Meatloaf Using Sous-Vide Technology
We have always been curious to work with the cheapest products. This time we chose store-bought ready-made minced meat, labeled "homestyle"—made of pork and beef—purchased from Metro Cash & Carry. We added salt, pepper, and a bread roll soaked in milk to the mince. We then whipped the mixture in a planetary mixer.
After preparing the mixture, we placed it in a plastic PET tray and inserted the tray into a vacuum bag. During vacuuming, the air entering the tray increased its volume almost twofold and it was pushed out of the bag. We had to reload the bag with a new batch of the meat mixture. This time we put in exactly 50% less than the first time. This time everything went smoothly. The mass doubled in volume and then returned to its original size when the air suction cycle kicked in. We placed the tray in the bag into a gastronorm container with a thermal circulator at a temperature of 67.5 °C. The temperature was so high because the mince was clearly dominated by pork, which requires a much higher processing temperature than beef. The product was cooked for 1 hour 25 minutes. We then removed the package, took it out of the bag, and cut the meatloaf into 20 mm thick slices, placing them on a baking sheet. The top was glazed with a ready-made Santa Maria pineapple sauce mixture. The product was then baked in a combi-steamer at 200 °C for 12 minutes.
Weight loss was 12% after cooking and another 3.5% after convection.
Experiment 4. Turkey Shawarma Cooked in Sous-Vide
Shawarma (also shaverma, shawarma, shuarma, shoarma; from Arabic شاورما, Hebrew שווארמה, from Turkish çevirme), in some countries called döner kebab or doner (Turkish: döner kebab), is a Middle Eastern dish (probably of Turkish origin) consisting of pita or lavash filled with chopped fried meat (lamb, chicken, pork, less commonly veal, turkey) with spices, sauces, and fresh vegetable salad.
Shawarma originally referred to a Turkmen dish invented by steppe shepherds—boiled saiga or gazelle meat is finely chopped and placed into the washed stomach of the same animal, along with its fat. The stomach is then sewn shut. It can be stored for several months without spoiling.
We prepared Israeli shawarma from turkey. We cooked turkey fillet pieces in sous-vide for 1 hour at 58 °C.
We then prepared an Arabic salad (tomatoes, cucumbers, lemon, black pepper), fried French fries, sliced pickles and pickled peppers, prepared tahini, pan-fried the turkey meat, wrapped the ingredients in lafa-style pita (Armenian lavash), and placed it in the combi-steamer for 5 minutes at 200 °C.
Video of the experiment: http://www.youtube.com/watch?v=Nwv_k0lZf6I&feature=player_embedded
Experiment 5. Salmon Steaks Cooked in Sous-Vide
The purpose of this experiment is to select the optimal temperature for thermal processing of salmon using a sous-vide thermal circulator to achieve the best taste, texture, and color of the product. Within the framework of this experiment, we will also identify the thermal processing extremes at which the product loses its appeal. The experiment uses half-steaks of salmon weighing 90 g after skin and bone removal. The salmon is rinsed and placed in a 10% saltwater solution at about 15 °C to prevent intense protein coagulation during processing.
The product is then placed into a 20×30 cm vacuum bag. It is at this moment that salt, spices, and herbs are added to the product. In this experiment, we used no additives.
We recommend vacuuming one piece of product per bag if the serving will be textural. In the case of non-textural serving (e.g., adding salmon to a salad), 2–3 pieces can be placed together to save on bags.
Important!
Pour hot water from a kettle into the sous-vide container before setting the circulator to operating mode. Do not place the product in the bath until the circulator signals that it has reached the set temperature. It is recommended to place the vacuum-packed product in a medium-temperature refrigerator for 24 hours for additional fermentation.
Vacuuming of the product is recommended for no more than 40–45 seconds, or by setting the vacuum to 50% (depending on the vacuum machine model). In this experiment, a Jambo mini vacuum machine from the Dutch company Henkelman was used.
Salmon is a very soft and porous product, so it should be processed in the biokinetic temperature range of 35 °C–50 °C for no more than 20–25 minutes.
Below is a table of recommended processing temperatures for salmon, developed by Foodinmind (Johannesburg)—the largest supplier of fish and seafood in Africa.
| Sous-Vide Processing Temperature | Processing Time (min) | Result |
|----------------------------------|------------------------|--------|
| 48 °C | 15 | There is a slight difference between salmon cooked for 15 minutes and 20 minutes. The product looks very attractive, resistant to tearing, muscle fibers are quite firm, gelatinization is insignificant. 15 minutes gives a classic rare option, while 20 minutes gives medium rare. Among all tests, processing at 48 °C for 20 minutes gave the best result. |
| 48 °C | 20 | |
| 50 °C | 15 | At this processing, a difference begins to be felt compared to the 20-minute processed salmon. The product became noticeably firmer and gelatinization increased. The aroma of the product intensified. |
| 50 °C | 20 | |
| 52 °C | 15 | Significant changes in color appeared. The intensity of pigment breakdown increases, and the product becomes paler—pale pink. Slight graying of protein appears on the sides. |
| 52 °C | 20 | |
| 48 °C | 30 | This processing was intended to find out how long salmon can remain in water. At 30 minutes, no significant changes were observed. When opening the bag, the juiciness of the product was preserved, texture and color were also acceptable. Tissue fibrillation is insignificant but greater than in the first treatment. |
| 48 °C | 40 | |
| 50 °C | 25 | The color became paler, and 20 minutes after removal from the bag, significant surface drying of the product was noted. Weathering appeared. |
| 50 °C | 40 | Fibrillation is increased. The product differs texturally from previous samples. |
| 48 °C | 60 | The texture of the product is impeccable, and the color turned pale pink. |
It is important to note that cooking salmon and any other salmonid fish in sous-vide often has a continuation in the form of finishing on a grill or pan for browning. Combined cooking of red fish is practiced by most leaders of sous-vide schools worldwide.
Our experiment differed somewhat from the African specialists in both cooking time and temperature regimes.
We worked according to the Douglas Baldwin table, shown below, and obtained equally impressive results.
| Thickness mm | 101°F (38.5°C) | 116°F (47°C) | 126°F (52°C) |
|--------------|----------------|--------------|--------------|
| 5 | 2 | 2 | 2 |
| 10 | 7 | 7 | 7 |
| 15 | 15 | 16 | 16 |
| 20 | 26 | 28 | 28 |
| 25 | 41 | 43 | 44 |
| 30 | 59 | 1:02 | 1:03 |
| 35 | 1:20 | 1:24 | 1:25 |
| 40 | 1:44 | 1:49 | 1:51 |
| 45 | 2:11 | 2:18 | 2:21 |
| 50 | 2:42 | 2:49 | 2:53 |
| 55 | 3:16 | 3:25 | 3:30 |
The results are shown in the photos: http://www.slideshare.net/pitportal/slamon-sous-vide-rare-and-medium-rare?from=ss_embed
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