Sous vide is all about precision and control. If you cook at the right temperature, and for the right period of time, you will get great results. Successful cooking is all about your food reaching the correct temperature. This means that the center of your food must achieve the right temperature, and it is not based just how long you cook an item of food for.
The accuracy of the cooking temperature is more important with some foods than with others. This means a few degrees here and there will not affect some foods, but will have a critical impact on others. Eggs are a good example of where the cooking temperature is very important.
The Problems With Conventional Cooking
When you use a high heat stove to cook, your food will be cooked under higher temperatures than the optimum internal temperature for perfectly cooked food. Successful cooking this way needs to be very well judged. Just before an item of food reaches its desired internal temperature, it must be removed from the heat.
This is because the outer edges of the food will be at higher temperatures than the center of the food. Once removed from the heat, the temperature of the center of the food will still be rising as heat will travel from the edges. This is not always easy to get right.
If you remove the heat from your food too early then you run the risk of undercooking. If you wait too long to remove the heat then your food will be overcooked. The other problem is that even if you get this right, you will find that your food will never be evenly cooked, because the edges will always be at a higher temperature than the center.
Precise temperature control with a conventional oven is difficult. Most ovens have a sensor which monitors the inside temperature of the oven. If the temperature drops, then the thermostat will kick in the heating element to raise it up again. This will cause temperature fluctuations in the oven, as it is being controlled by a basic on and off switch.
In normal ovens a 20°F variant in temperature can be expected. If you set your oven temperature to 400°F, it is likely that the temperature inside the oven will vary between 380°F and 420°F. This will be OK for some of the food that you cook, but other food types require precise temperature control for the best results. The other thing to bear in mind is that the temperature in the oven will vary in different places, because air is not a good conductor of heat.
Sous Vide Cooking Temperature Control
Because your food is immersed in water with sous vide cooking you can be sure of great cooking results. The temperature in all parts of the water bath will be the same due to the circulation of the water. Water also conducts heat significantly better than air does.
Most sous vide machines have a PID controller, which ensures that the temperature of the water bath is controlled precisely. It doesn’t matter whether you use a self contained suvee cooker (the water bath is part of the cooker) or an immersion circulator, you can be guaranteed that the cooking temperature will always be precise. You will experience the benefits of sous vide cooking with either machine.
The real secret to successful sous vide cooking is that the food will be cooked until the center achieves the desired temperature. There is little danger of overcooking despite the cooking time of your food. There will be no overcooked edges either, as sous vide cooking ensures that your food will be evenly cooked, due to the external temperature being the same as the desired cooking temperature.
A PID controller will prevent changes in the cooking temperature before they occur. It will estimate temperature changes using proportional, integrative and derivative assessments to do this. Using this logic, a PID controller knows when to turn the heating element on or off if it estimates the smallest of temperature changes. It is a lot more precise than conventional ovens, and the best sous vide cookers can maintain the cooking temperature to 0.01°C.
Sous Vide Cooking Times Are Important Too
You can change the cooking time and the cooking temperature to produce different results with suvee cooking. There are a few things to be taken into consideration here, which are the shape and thickness of the food you intend cooking, and the initial temperature of the food (is it frozen or at room temperature etc).
Remember that the internal temperature of the center of your food is very important. You will see below the recommended cooking temperatures for all kinds of food. With sous vide cooking it is necessary to change the cooking time for your food in certain situations.
An example of this is the tenderization of meat. If you are cooking a tough meat like short ribs or brisket, then you will get a more tender result if you cook for longer in the water bath. It is possible to make these tough cuts really tender, and still be either medium or medium rare by cooking for longer periods. You will need to cook this type of meat at the correct temperature for at least 6 hours to 3 days.
You need to be aware that there is a maximum time to cook your food sous vide. If you cook fish or chicken for too long, the inside can turn to mush. For fish this can occur just a few minutes after the recommended cooking time has elapsed. With chicken this can be after four hours of cooking time. Overcooking beef cuts will not normally have any detrimental effect on the food.
Recommended Sous Vide Cooking Times For Popular Foods
For light meat chicken that is tender and juicy cook at 65°C (149°F) for between 1 and 2 hours
If you want darker meat chicken which is still tender and juicy cook at 75°C (167°F) for between 1.5 and 3 hours
For flaky and tender fish cook at 50°C (122°F) for between 40 minutes and one hour
If you are cooking a beef steak sous vide and want it to be medium rare then cook at 58°C (136°F) for between 1.5 and 3 hours
For medium rare roast beef cook at 60°C (140°F) for between 6 and 14 hours
To get wonderful poached eggs cook at 65°C (149°F) for between 1 and 2 hours
For that perfect medium rare pork chop cook at 62°C (144°F) for between 1 hour and 1 hour 45 minutes
If you want a whole potato to be very tender then cook at 85° (185°F) for between 1.5 and 3 hours
For really tender green vegetables cook at 85° (185°F) for between 5 minutes and 20 minutes
You will need a best sous vide machine to obtain the best results. You may decide to go for an immersion circulator rather than a self contained cooker, as these are much smaller and you are not so limited with the size of water bath you can use.