On this page we have some answers to the most important questions about sous vide in general, the process and fusionchef. Our cumulative questions and the answers provide a first look at the sous vide subject. Chefs can receive feedback on their very specific questions regarding their professional kitchens. If any questions should remain unanswered, please contact us and state your question.

The sous vide cooking method reduces cooking food shrinkage to a minimum and the Pearl will already pay for itself with the savings on food shrinkage after sous vide cooking circa 170kg of beef tenderloin.

fusionchef offers custom fitting retaining grids for the XS, S, M, L and XL sous vide cooker in order to hold the vacuum bags under water. The retaining grids can be placed on top of the fusionchef sous vide water bath to guarantee the food is equally heated on all sides.



Steaming and sous vide cooking are different methods which complement each other extremely well in a professional kitchen. The steamer is predesigned for larger quantities and frequently recurring products. On the other hand fusionchef sous vide instruments are ideal for smaller portions and have a clear advantage when products change frequently. This synergy has been realized by many chefs and they successfully use fusionchef sous vide instruments in addition to a steamer.

If the core temperature sensor is used in conjunction with the special fusionchef adhesive sealing tape, then the puncture point in the vacuum bag is sealed and the vacuum will be maintained. It cannot be completely ruled out that water from the water bath does not come into contact with the food. Therefore, for hygienic purposes, products that are stabbed with the core temperature sensor should not be served. They are to be used only as a reference sample for similar sized pieces of the same product.

The fusionchef sous vide instruments have been designed for the use in professional kitchens. All constructional and technical characteristics are geared to these professional demands.

fusionchef offers custom fitting separation grids for the XS, S, M, L and XL sous vide instruments in order to divide the water bath into sections. The cooking products can then be divided by time needed and easily identified to be taken out at different times.

Because stainless steel can corrode, please pay attention to the following instructions in order to prevent and protect the sous vide machine against rust and corrosion:

  • Do not clean the sous vide thermostat and the sous vide water bath with steel wool.
  • Do not add salt to the temperature regulated water.
  • Chlorine in drinking water can cause corrosion.
  • Iron containing drinking water can cause rust to form due to the flocculation of the iron when heated.

We recommend using several fusionchef units when simultaniously working with different cooking temperatures and cooking various foods (e.g. meat, fish, vegetables). With the help of multiple fusionchef units, different temperatures can be controlled and a complete menu can be developed at the same time.

Another option is to use the core temperature sensor for the Diamond. The Diamond sous vide thermostat can be set to heat the water to the highest temperature needed for the first food, meanwhile another food requiring a lower temperature can be controlled by the core temperature sensor. When the desired core temperature of the second food is reached, immediately remove it from the sous vide water bath. It is ready.

fusionchef instruments are constructed for continuous use under normal circumstances. It is not necessary to service the units on a regular basis.

All fusionchef sous vide instruments are meticulously tested and calibrated before leaving our factory. They are designed for precise, continuous operation. It will take a long time for the instrument´s sensors to lose a very minimal amount of precision if any. Only after many years, can there be slight differences. Therefore it is not necessary to calibrate the fusionchef thermostat under normal conditions.

Sous vide (su:'vi:d) is French for as “under vacuum“. It describes an especially gentle cooking method which is also known as low temperature cooking.

Sir Benjamin Thompson, Count Rumford was the first to describe the sous vide method, i.e. low temperature cooking in 1799. The benefits of the procedure, however, were not recognized before the mid 1960s in France and were used to reduce food shrinkage. Today, star chefs all over the world apply this technique because of its numerous advantages.

When cooking sous vide, fresh food such as fish, meat or vegetables are vacuum-packed and then cooked in precisely temperature-controlled water.

Every fusionchef comes with an integrated circulation pump with a capacity of 14l/min. It is responsible for the continuous circulation of water in the vessel and results in a constant temperature within ± 0.01°C of the set temperature in the entire sous vide water bath or external cooking vessel.

In addition to a fusionchef instrument, you need a vacuum packing machine and cooking bags.

Vacuum packing machine

Generally there are two types of vacuum packing machines: professional chamber machines and home vacuum packing machines without a chamber. For professional use in restaurants and catering we strongly recommend a chamber machine since vacuum values can easily be changed to individual settings.

Cooking bags

Three types of cooking bags may be used with chamber machines: edge sealed bags, tubular bags and shrink bags. Edge sealed bags (also called 3-edge bags) have 3 sealed sides. Tubular bags have no side seams and are sealed only on one side. Therefore, they are more solid than edge sealed bags. Nevertheless, both types are suitable for sous vide cooking. Shrink bags cover the food like a second skin: only little liquid forms in the bag.

Check the temperature resistance of the bags! This should equate to the cooking temperatures (40 °C – 90 °C) and the bags should not be affected by rapid cool-down or shock freezing.


Always turn off and unplug the sous vide instrument before cleaning it. Be careful not to allow any water used in cleaning to seep into the machine.
Do not clean a fusionchef sous vide machine with a jet of water or submerge it into water. Do not lay the sous vide thermostat on its head - doing so will allow water to seep into the machine.


Wash the stainless steel water bath and the functional parts (circulation pump, float, and the heater) with a mild soap solution. Rinse the bath and parts with filtered water and diligently wipe all the parts dry with a soft towel. Do not lay the machine on its head! Rub down the outer sides with a towel and the mild soap solution.

Finally, check the low-level safety feature. Hold the sous vide thermostat perpendicular to the countertop and test the ease of movement of the float.

As with other dishes such as sushi and tiramisu there are also risks when cooking sous vide. If you consider a certain time factor most germs and bacteria are usually killed at a temperature of 55 °C. Growth of bacteria can be reduced by immediate consumption or by cooling the cooked food to 3 °C.

There is no scientific proof that serious dangers originate from sous vide cooking. Make sure to always use fresh food and to comply with hygienic requirements.

1. Intense flavor experience for your guests
The sous vide technique facilitates the preparation of nutritionally healthy and vitamin-rich foods. When using conventional cooking methods vitamins and flavors are released into the water or the air. However, when using the sous vide method the fresh food is vacuumed and all vitamins and flavors remain concentrated in the food. The final product contains not only all the vitamins and nutrients which normally are lost, but also the full flavor of the food. This ensures a more intense taste. Freshness, color and appearance remain unaltered until consumption.

2. Always perfect results in your kitchen
The sous vide technique offers the possibility to cook food perfectly with complete control of the two main factors: temperature and time. Steady heating in a water bath allows for even cooking from the edge to the core of the food. For example if you fry a piece of meat in a pan, it is exposed to extremely high temperature on the outside, while inside it sometimes does not reach the temperature required for a perfectly cooked product. Sous vide allows for even doneness of the final product. Dried out food is avoided.

3. Best quality, every day
The sous vide method guarantees reproducibility and consistently good quality. Once you have determined the optimum temperature and time for a certain recipe and given the same conditions (size, fat content, etc.) the medium can be reproduced exactly time after time.

4. Cost savings on raw material
The sous vide technique minimizes portion losses due to shrinkage especially when cooking meat.  Meat shrinks by about 40% of its original size when using conventional cooking methods. The sous vide method minimizes the shrinkage to a maximum of 5-10%. Product costs and portion losses are reduced considerably.

5. Optimal preparation of meals - Cook & Chill
Quickly cooling pasteurized food down to 3 °C after cooking allows for chilled storage of the food for up to 3 weeks. The portions can be regenerated as needed without any loss in quality. This facilitates more efficient planning of food purchases and consumption as the loss of food is significantly reduced. In addition, the guaranteed longer shelf life assists with optimization of the quantity of food ordered.

6. Environmentally friendly – Energy efficiency
fusionchef units have low power consumption and a limited need of water which significantly saves energy in the kitchen.

7. Improved workflow in your kitchen
The increased shelf life of sous vide prepared products makes the workflow in your kitchen more efficient. Products can be prepared during stress-free periods and are prepared quickly yet with high quality during rush hours. The simplified workflow permits the kitchen to offer a wide selection of dishes.

1. Preparation

Use only the freshest and best ingredients. Prepare the raw, uncooked food.
sous vide fusionchef Vakuumieren.


2. Vacuuming

Place the raw, chilled ingredients in bags suited for sous vide cooking and seal them using a vacuum packing machine.


3. Cooking

Fill the bath tank with hot water and heat it to the desired temperature using your fusionchef by Julabo unit. When the desired temperature is reached, place the bag containing the product into the water bath. Always cook gently at low temperatures, but for a longer period of time. If you do not have experience regarding cooking times and temperatures, be sure to consult a sous vide cookbook.


4. Cool

If you do not serve the cooked product immediately after cooking, you can cool it and place it in chilled storage. Cool the product after cooking to 3 °C within 90 minutes. This can be done in a bath of ice water or a shock freezer.


5. Chilled storage

Remove the cooled bag from the ice water and store the product at maximum of 3 °C.


6. Regenerate

Heat the cooled bag just before serving.


7.  Searing

Sear the food just before serving. The food develops its fresh flavor once more (Maillard reaction).


8. Serve & Enjoy



For example, a fusionchef Diamond M consumes ca. 6.5 kW while operating for 18 hours. The calculation is based on the following prerequisites:
The water´s stating temperature in the fusionchef sous vide water bath is between 15  ̊C and 20  ̊C
When the set temperature is reached, a kilogram of Sauerbraten (core temperature of +3  ̊C) is placed into the sous vide water bath and is cooked at 60  ̊C for 18 hours.

Only use decalcified water in a fusionchef sous vide instrument. The water should be changed on a regular basis. We recommend it be changed daily.
Not changing the water on a regular basis

  • can increase the concentration of minerals in the water from the continuous refilling, which will create a crust on the sous vide thermostat and the sous vide water bath.
  • can result in contamination of the vacuum bags from particles in the water.

We recommend that you proactively descale your fusionchef on a regular basis before hard water deposits are visible. How often you need to descale will depend on the hardness of the water used in the machine. In order to protect your fusionchef from calcium deposits and for the safe removal of hard water deposits, we offer an effective descaler in our fusionchef line of accessories.

Sous vide cooker accessories descaling agent (1 liter)

In order to maintain optimal water circulation and a constant temperature inside the sous vide water bath or external cooking vessel, we recommend, as a general rule of thumb, not to cook any more than about half of the water bath volume in kg of food.

XS Sous vide water bath by fusionchef or GN 1/2 200 mm (13 liters):       up to circa 5 kg
S Sous vide water bath by fusionchef or GN 1/1 150 mm (19 liters):            up to circa 8 kg
M Sous vide water bath by fusionchef or GN 1/1 200 mm (27 liters):         up to circa 12 kg
L Sous vide water bath by fusionchef or GN 2/1 150 mm (44 liters):           up to circa 20 kg
XL Sous vide water bath by fusionchef or GN 2/1 200 mm (58 liters):       up to circa 27 kg



The protective grid must be removed in order to carefully clean the functional parts (circulation pump, float, and the heater).
Important: The machine must be turned off and the electrical cord must be unplugged! Do not lay the sous vide thermostat on its head - doing so will allow water to seep into the machine!

Take the sous vide thermostat out of the sous vide water bath and diligently dry it. Do not allow any water to seep into the machine.
Turn the sous vide thermostat on its side and lightly push the edge of the metal housing to the side. Then pull the protective grid down. After cleaning the protective grid, remount it in the reverse order.

After that, check the function of the low-level safety mechanism: test if the float can easily move by using a thin pin through the opening in the protective grid.

Each fusionchef sous vide model (XS, S, M. L and XL) comes with a drain valve that needs to be inserted in place of the integrated screw plug before the first use. To empty the water bath, turn off the sous vide thermostat and unplug the machine. Place the sous vide machine over a drain or place the drain valve over a large enough vessel. Open the drain valve and let the water flow out.

Powerful, integrated pump

fusionchef units feature a pump which circulates 14 l/min, providing excellent water circulation in the bath.

High temperature stability

The turbulence of the water and precise electronic control obtain maximum temperature stability. fusionchef instruments maintain the desired temperature with an accuracy of ± 0.1° C.

Fast heat-up

Efficient processes in a professional kitchen require instruments which are ready for use and reach the desired cooking temperature in a short amount of time. Independent of the bath size, fusionchef instruments need very little time to heat-up.

Low maintenance effort

Professional sous vide instruments should be designed for intensive usage and continuous operation. fusionchef instruments require no prescribed maintenance interval. fusionchef only recommends changing the water regularly, cleaning with a detergent suitable for stainless steel and occasionally descaling the instrument.