The Science: How Does Sous Vide Work? | The Tool Shed

The Science: How Does Sous Vide Work?

If you’ve tried sous vide for yourself, you’ll know that it produces incredible, restaurant-quality results, but have you ever wondered exactly how it works?

Sous vide cooking itself is as simple as vacuum sealing your ingredients, selecting a cooking temperature and time and leaving them to cook, but there’s actually a lot of science going on behind the scenes.

The Problems with Traditional Methods

What it ultimately comes down to is the fact that water is a much more effective way to transfer heat to food than via air (in an oven) or a hot piece of metal (in the case of a pan).

The goal in cooking is usually to bring the food which you’re cooking to a specific temperature, at which it is considered to be perfectly cooked.

This means that if you’re using these more traditional methods of cooking, you’ll need to set the temperature a lot higher than the desired temperature of the food to reach this point.

However, with lots of foods, such as fish and steak, the margin for error is very small which opens up the risk of overcooking or burning the food if you’re not careful.

As an example, let’s say you’re cooking a steak on the grill which you want to be medium rare (an internal temperature of about 56˚C) with the grill set to about 210˚C.

This means that the outside of the steak will be well done well before the core reaches the desired doneness, forming a large temperature gradient between the surface and the core, even though you’re only grilling for a short space of time.

Alternatively, if you’re cooking in a pan, the surface of the pan could be about 30 degrees hotter than the centre, and if you leave the steak for just a little bit too long at these extremely high temperatures, it’ll be overdone and tough.

The Sous Vide Solution

However, this is where sous vide comes in. Because water transfers the heat a lot more efficiently, the food is cooked a lot more gently, and held at exactly the right serving temperature without exceeding it.

So for the example of our medium rare steak, it’ll simply be held at 56˚C (with an accuracy of as much as 0.1˚C) until it’s evenly cooked throughout, without ever overcooking, meaning you don’t have to worry about timing.

Holding the food at an exact temperature might make more of a difference than you’d think, because just a couple of degrees either way can make a big difference.

The importance of temperature control is best illustrated with eggs, with which the proteins break down at between 54˚C and 71˚C.

That’s quite a big range, and obviously, the eggs are going to cook a lot quicker the higher the temperature.

So, for example, if you cooked eggs sous vide at the lower of this range, you’ll get a loose white (runny and clear).

However, with just a few more degrees, the whites will start to solidify, but the yolk will remain runny.

A few degrees more and you’ll get something closer to a hard-boiled egg, so you can see just how important the accurate control that sous vide gives you is.

(Check out our Guide to a Perfect Egg to see exactly how to get your eggs just how you like them!)

Something you’ll also notice with sous vide is that it gives you a very tender meat. This is because it effectively breaks down the collagens and proteins which make food tough and chewy, but preserves the muscle and other important parts which provide texture and taste.

Vacuum Packing

Vacuum packing is also an important aspect of sous vide cooking. This process is crucial because it stops air from insulating the food and slows the rate of oxidation, which can lead to unwanted colour changes and strange tastes.

It’s also important for locking all of the nutrients and other good stuff into the food, as these would be leached out into the water if they weren’t securely vacuum sealed.

This is especially good when cooking steak, as all the juices are retained and could even be kept and used in a sauce if you wished.

Now that you’ve got a slightly better understanding of exactly how sous vide works, what are you waiting for?

Check out our full range of home sous vide machines here and see the results for yourself!

Post by Chris Holland

Our Chef Director Chris Holland worked as Head Chef at the prestigious Alderley Edge hotel before joining us. He has a passion for using the best produce and never compromises on quality. Author of our best selling book Sous Vide The Art of Precision Cooking, Chris is a expert on the sous vide technique.During the later part of my school days at Wardle High School Rochdale I always wanted to be a chef . I knew from the very start that my path to work was never going to be academic it was always going to be something practical and hands on.

As a young boy growing up I was inspired to cook with my Grandma who was and still is an inspiration to me . I have memories of helping make the cakes that she always had made for visitors and family alike . She made the most amazing cakes and I loved nothing more than eating the sweet raw cake batter straight from the bowl . We used to fight over who got to lick the bowl/spoon after the cakes were made. My grandma’s philosophy for cooking even on a shoe string budget was always to use fresh and seasonal ingredients either home grown or bought from the market.

School was somewhat of a drag for me as I was itching to learn to become a chef.

I started at Hopwood Hall college as a chef and instantly fell in love with it .To me it was the only real time I excelled in something and this inspired me to really get my head down and put in the hard work. College was the first time I really excelled in something and gave me the opportunity to laugh at the teachers who said I would never make something of my life!!!!

During the three years at college I also took on a part time position in a local hotel working the bar and restaurant first and then the kitchen. These were great days and gave me the opportunity to see how the industry ticks. I learnt a lot from those days both good and bad !! But I have to say I was itching to work only in the kitchen but it was a good insight into the catering world .

After completing college I moved away from Rochdale for a full time roll at one of Cheshire’s most talked about Hotel restaurants The Stanneylands Hotel. This was the school of hard knocks for me as I quickly realised that although excelling at college meant nothing in “The Real World”.

I loved every minute of the 18 hour days 6 days a week on minimum wage . Although difficult I feel that without this grounding I wouldn’t have achieved what I have today. After 18 months of hard graft I left Stanneylands and went with the Head chef to open a fine dining restaurant at Mere Golf and Country Club. The opportunity to work alongside Matthew Barrett was too good to turn down. I learnt so much from the ex-Ritz chef and working in a much slower paced role helped me develop a much better understanding of how to organise and run a kitchen. We were a very small team and teamwork was and still is the only way to go for me.

After 2 years at Mere I got the opportunity to go into The Alderley Edge Hotel as Junior Souschef. The Early days at the Edge were all about learning new styles of cuising which is invaluable in any role as a chef. I got the opportunity to grow and learn all aspects of every section which was inspiring . I was offered the opportunity at the age of 29 (2004) to take the role of head chef. For me this was when I really started to develop my own style of food.

After 9 years at the top winning Cheshire restaurant of the year , Chef of the Year and appearing on GBM amongst many highlights including cooking for many celebrities and famous people I decided to move on into development with Sousvidetools.

The main inspiration for this was to train and educate people . I always had a great passion for education but could never really see myself at a college . The job is super rewarding and I am proud to say we have become the leading light in sous-vide education in the UK . This is something I am very proud of . Food is my biggest passion and this is what keeps me interested the most . I love to travel and try out other countries cuisines. I am constantly inspired by ingredients and the pursuit of getting the best out of them without destroying their natural flavour .It is super important to me to continue to try and be at the forefront of the food scene this is what inspire me and the team to keep driving forward .

Technology is now widely used in the industry and I am super proud to say we have been a big part of spreading that message.

I am very lucky to be in the position I am and the drive to constantly improve our training and links to the next generation of young budding hospitality chefs.

TI feel that my experience over the last 25 years really enables me to get close and educate the “next generation” of chefs .

The industry which I love is really struggling to bring through new recruits and if I can help that process I will be immensely proud.

The food seen in the Uk has improved dramatically over the last ten years and I feel this will continue with the correct education. What happens next only fate will tell us...

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