Sous vide – the essential guide

by Tom Shingler30 October 2015

A brief introduction to the culinary technique of sous vide – cooking under vacuum – and the equipment needed to cook ingredients this way, both in professional kitchens and at home.

Tom Shingler is the former editor of Great British Chefs.

Tom Shingler was the editor at Great British Chefs until 2021, having first joined Great British Chefs in 2015.

Tom Shingler is the former editor of Great British Chefs.

Tom Shingler was the editor at Great British Chefs until 2021, having first joined Great British Chefs in 2015.

Sous vide (soo veed) has been the secret of professional chefs for years as it allows them to cook amazing dishes consistently in a simple, stress-free way. It involves submerging vacuum-sealed bags of food in heated water which then cooks the ingredients to perfection.

Until recently, the equipment was too expensive for home kitchens, but it’s now much more affordable and incredibly popular with serious amateur cooks. Here’s a brief guide on the different pieces of kit you need to get started and how they work.

Hot water

While sous vide literally translates to ‘under vacuum’, being able to heat water to an exact temperature is just as important as the vacuum process. This is where water ovens or thermal circulators come into play. They both serve as a heater and thermostat, so you can just leave them to maintain your desired temperature.

Water ovens are countertop units you fill with water. The base then heats the water evenly to keep it at the set temperature.

Thermal circulators work in the same way, but are clamped on to the side of a separate container and use a motor to circulate the water to maintain the correct temperature.

Both machines have their advantages; water ovens don’t need to circulate the water, so they run silently, and they’re all set up and ready to use at any time. Thermal circulators are more suited to the occasional sous vide cook as they can be detached from the container and easily stored away.

Under pressure

Heating water to a precise temperature is one half of sous vide cooking – the other involves placing your ingredients in a pouch and sealing it under vacuum. This requires a machine that can suck all the air out of a bag and seal it. Not only does this prolong the freshness of some foods, it also allows the food to be fully submerged in the water oven in direct contact with the heat of the water resulting in even and consistent cooking. There are two types of machine you can use – vacuum sealers and chamber vacuum packers.

With bar vacuum sealers, you simply feed the open end of your vacuum pouch into the machine and turn it on. It removes all the air inside, then seals the bag by slightly melting the plastic together with a heating strip.

Chamber vacuum packers are for the more serious sous vide cook. Instead of inserting your pouch into a slot, you place the whole thing inside a box, which then removes all the air in the entire chamber, not just the bag, before sealing. This means there’s no difference in pressure outside the bag, so there is less risk of liquids being sucked out with the air. Overall, they’re more powerful, reliable and quicker to use than vacuum sealers, but do come with a higher price tag.

Placing the vacuum bag in the chamber
The bag is sealed with all air removed

Going further

Once you’ve got your water oven or thermal circulator, a vacuum sealer and food-grade plastic pouches, you’re all set for sous vide cooking. But there are a few other bits of kit which will further enhance your incredible new dishes.

A vacuum canister is a simple, affordable food container that attaches to your sealer, which in turn removes all the air out of it. Canisters are mostly used for marinating, preserving and infusing; you just place meat, fish or vegetables inside, pour over your sauce, marinade or pickling liquor and the vacuum will force the liquid into the food, achieving the desired results in hours rather than days.

A good thermometer is vital for precision cooking, which is, after all, what sous vide cooking is all about! A piece of special foam tape stuck to the side of a vacuum pouch means you can push a probe through it without any risk of pressure loss, so you’ll know exactly when your food hits the perfect temperature.

Once you’ve got to grips with the essential equipment and caught the sous vide bug, keep trying new things. Using the kit at home gives you the freedom to experiment, and because it’s still a new cooking method, you might just create something incredibly exciting – the sky really is the limit!

Get in touch

Please or register to send a comment to Great British Chefs