When someone like Heston Blumenthal describes a piece of cooking equipment as having the ability to ‘revolutionise cooking in ways that the microwave didn’t dream of doing’, we tend to sit up and listen. Heston is, of course, referring to the Sous Vide cooker which he uses widely in his fabulous Michelin starred restaurants as well as on TV. Thankfully Sous Vide cookery is no longer the exclusive preserve of biochemically inclined uber-chefs; Steamer Trading is delighted to offer a complete range of equipment to bring this exciting and tempting new method of cooking directly into your kitchen.
Sous Vides translates to ‘under vacuum’, essentially your food is sealed in a food safe plastic bag and cooked in a water bath at a precisely controlled temperature. This method is extremely effective at locking moisture, flavour and nutrients into your food. It also prevents over cooking and allows the foods’ natural texture to be fully appreciated.
How do you use a Sous Vide?
Imagine that you’re pan-frying a steak or a salmon fillet. Your aim is to heat the food so that the centre of the steak or fillet reaches around 55° Celsius. To achieve this, the surface temperature of the pan will be upwards of 200° Celsius. This means that when the inside of your steak reaches the perfect temperature, much of the outer part will be over cooked and grey. The frying process will have driven moisture out of the meat leading to shrinkage and a chewy overall result.
The sous vide heats the food to precisely the right cooking temperature and holds it there until the food is cooked through and ready to serve. To cook your steak using the sous vide method you simply seal it into a vacuum pack, set the water bath on your sous vide cooker to precisely the desired temperature, and place the bag into the water. As the steak is sealed in the bag there is no possibility that any moisture can be lost. As a consequence your steak will retain all of its delicious juices as well as its natural flavour. The slow and gentle heating that the sous vide provides means that the cooked steak will also have an unsurpassed level of tenderness that has to be experienced to be believed.
To achieve their remarkable results, sous vides operate at low temperatures, below 100° Celsius, with extended cooking times to allow the food to thoroughly heat through. It may take 57 minutes to poach an egg in a sous vide but the results will be remarkable as it can be cooked to the exact temperature where the proteins begin to coagulate. With your sous vide you’ll never eat a leathery egg again!
Can I only cook meat in my sous vide?
You can prepare almost any food that you like using a sous vide. Vegetables retain their colour, texture, nutrients and the sous vide will ensure that the delicate flavours and texture of fresh fish or chicken are maintained at their best. Prawns and scallops are a revelation when cooked in the sous vide. You can even use it to make perfect custard!
How critical are the cooking times?
It takes a long time for food to be thoroughly heated when using low cooking temperatures. In this respect, sous vide cooking is very much like conventional slow cooking. Cooking times depend greatly on the thickness of the item being cooked. It’s not a very good idea to cook food in your sous vide for less than the recommended time. However, unlike conventional cooking methods it's very difficult to overcook food in your sous vide. This is because the cooking temperature and the serving temperature of the food are the same. Once the food has reached the cooking temperature it doesn't get any hotter so the texture of the food will not change. As the food is sealed in a vacuum pack none of the juices can escape to extra heating won't result in the food's drying out either.
Does the sous vide brown my food?
The low temperatures that the sous vide uses to cook food aren’t enough to brown the outsides. This is why many chefs like to quickly flash fry a steak that has been cooked in a sous vide for a few seconds to add colour. Some chefs recommend that you finish a roll of beef that has been cooked in the sous vide with a blowtorch to brown the outside without ruining the delicate texture of the cooked meat.
Why is precise control of the cooking temperature so important and is the food cooked at low temperatures safe to eat?
When we cook food, the heat makes the structure and the molecules within the food change. This is why egg whites go from clear, when raw, to white when cooked. With vegetables the plant cells burst when heated making the cooked veg softer but also releasing the sweet, flavourful content of the cells which may be lost during traditional boiling or roasting. When meat is heated the protein molecules change, which drastically alters the texture of the meat; at the same time fat and connective tissue melt or break down into gelatine which also affects the texture and toughness of the food. These changes happen at very specific temperatures.
We tend to think that foods have to be scalding hot to kill harmful bacteria. For the most part these high temperatures are recommended so that we can be sure that the heat has penetrated to the centre of the food to kill bacteria. The sous vide operates at lower temperatures but for longer periods to ensure that food is always heated through to the centre. Most foods that are prepared in the sous vide require a cooking temperature of 55°C or higher. This is the temperature at which food becomes pasteurised - the same process that is use to preserve milk. At this temperature both salmonella and botulinum bacteria are killed. We recommend that you use a good quality digital probe thermometer to check the core temperature of foods cooked in the sous vide, (remember that you can always reseal a vacuum pack if you open it to check the temperature).
Can I prepare food in advance using my sous vide and store it for later?
Sous vides are a great way of cooking food in advance to save time later. Chill the food immediately after cooking using an iced water bath. Your food can then be stored in the refrigerator for up to four days or put into the freezer for much longer storage. To reheat your food simply set your sous vide to the original cooking temperature and drop the bag in. Use your probe thermometer to check when the centre of the food has reached the correct temperature.