There is a kitchen gadget that is pretty much guaranteed to produce meals of extraordinary quality. It will cook a tough beef joint such as brisket so it is tender and tasty while still medium-rare. It produces fish with a clean, pure flavour and perfect al dente texture. Vegetables from the gizmo are fresh, juicy and bright in colour. Moreover, you can achieve these miracles without careful timing or fussing over the process. Five minutes one way or the other won't make much difference. You just leave the machine to get on with it.
This miraculous method is called sous vide (French for "under pressure"). Essentially, it involves a tank of hot water that cooks vacuum-packed foods at a precise temperature. Even if you haven't heard of it before, it is highly likely that you will have eaten sous vide food. It is so simple and reliable that many pubs use the technique for shrink-wrapped meals, often pre-prepared by commercial suppliers. Curiously, sous vide is also used by some of the world's top chefs.
The innovator who discovered the possibilities of the technique is a culinary scientist called Bruno Goussault. As early as 1972, he was exploring its benefits for the Wimpy chain. "Sous vide ushers us into the realm of temperature control so far unprecedented," he says. "It is likely to amaze us in the future as more chefs embrace it for their imaginative ends." Indeed, sous vide is now an essential weapon in the culinary artillery of such stellar names as Ferran Adria, Joël Robuchon, Heston Blumenthal and Charlie Trotter. "Precision heating offers unprecedented control over texture and flavour," explains Thomas Keller, chef/proprietor of Per Se in New York and the French Laundry in Napa Valley, in his book Under Pressure: Cooking Sous Vide.
But this culinary magic comes at a price. The US-made SousVide Supreme, described as "the first countertop water oven designed for the home kitchen", costs £349 and requires a fair bit of space. It is much the same size as a microwave oven. You will also need a vacuum sealer (£99) from the same manufacturer. And you need plenty of time for cooking. Sous vide is the polar opposite of Jamie's 30-minute meals. Forty-eight hours at 57C is recommended for brisket, belly pork takes 12 hours at 82C, while a boiled egg achieves perfection in a mere 60 minutes at 62.5C. To prevent the contraction of illnesses caused by anaerobic bacteria, such as botulism, which can multiply in air-free environments and survive low-temperature cooking, food should be fresh and cold when sealed and served soon after cooking.
Having borrowed a SousVide Supreme, I started with Thomas Keller's recipe for soft-boiled egg with green asparagus, crème fraîche aux fines herbes and butter-fried croutons. Nothing too difficult there, though I had a problem with the sous-vide egg. It was not clear from Keller's book whether the egg should be vacuum-packed before the long simmer. My wife thought yes, so I put four eggs in a plastic bag and sucked the air out. As the eggs bunched together in the tight grip of atmospheric pressure, they gently fractured. I then did two eggs in separate bags, which worked OK, but going back to the book I realised that the eggs should go in au naturel, so I added two more to the steaming tank, making eight in all.
An hour later, I cracked one of the eggs ("As you would a raw egg," Keller says) over a carefully arranged pile of seven steamed asparagus spears. It slithered over the bunched spears and, gathering momentum, tumbled to the edge of the plate and fell – plop – to the floor. Fortunately, we had plenty more sous-vide eggs. For the next one, I followed Keller's direction to "crack the egg over an empty plate". The reason is the distinctive nature of the 60-minute sous-vide egg – the yolk is very lightly set, but the white is like a wobbly jelly. The silky, flowing yolk went well with the crunchy asparagus, herby sauce and sweet croutons, but you were left wondering if a straightforward poached egg would have worked just as well, while being a sight less fuss.
Our next experiment – steak in browned butter from the SousVide User's Guide – was a knockout, no ifs or buts. One hour at 56C transformed two standard Sainsbury's rump steaks costing £4.68 into something like aged fillet. After being seared for 50 seconds per side in foaming butter, the steaks were tender, juicy and perfectly cooked. Within a caramelised crust, the meat had a brown margin and pink interior: the definition of medium-rare. With the plastic bag holding in all the flavour, the taste was excellent. Two haddock fillets, which were simmered in the bag with a slice of lemon and a smear of butter for 45 minutes at 60C, were equally successful. In both taste and firmness, the result was akin to halibut. "I now see the point of sous vide," said my wife, who had been put off by the messy egg débâcle. "It's almost worth £350."
Even for this amount, you don't quite get professional standards. Unlike commercial versions, the SousVide Supreme does not include a pump to circulate the warm water. Still, it seems accurate enough for home purposes. Perhaps a more significant weakness is in the vacuum sealer. On one occasion when we used it, this failed to expel all the air. On another, the heat seal failed and the bag opened slightly while in the sous vide. The vacuum sealer would not be powerful enough to make Keller's "compressed watermelon", which is said to have "the texture of an apple". On the other hand, a professional vacuum-packing machine costs from £350.
It may seem that sous vide is merely a sophisticated form of a slow cooker, but there is a difference. When braised, meat breaks down into fibres. With sous vide, it keeps its structure. This even happened when we used the device on oxtail. The result was less fibrous and held together better than a conventional braise. The flavour was excellent – but the same applies to oxtail braised for six hours in a casserole rather than the 14 hours required for sous vide.
The paraphernalia required for sous-vide cooking are among the simpler devices found in top-end professional kitchens these days. The freeze-dryer, food dehydrator, liquid nitrogen and microgel equipment required for the exquisite creations of Heston Blumenthal and Ferran Adria are unlikely to percolate through to the domestic kitchen. In his book A Day at elBulli, Adria advises readers not to attempt his recipes.
Perhaps we wouldn't find much use for these gadgets even if we got our hands on them. I once bought the pressurised whipper and nitrous oxide cartridges required for Blumenthal's Black Forest gateau. Having made the cake with immense effort, the impressive stainless-steel device disappeared into the cupboard, never to emerge. I rarely feel the urge to make the once-fashionable foams that are the prime raison d'être of the whipper.
Keller's book in praise of sous vide seems to be aimed primarily at fellow professionals (his recipe for tripe oreganata "makes 50 servings"), but his caramelised fennel with almonds, orange confit and fennel purée was a revelation. As he points out, "Fennel cooked sous vide epitomises the advantages of using this technique for vegetables." Notoriously tricky to get right, fennel often emerges from the pan overcooked and undercooked at the same time. It also tends to be the colour of putty. Simmered in the bag with herbs and a splash of Pernod for 40 minutes at 85C, our fennel proved to be perfectly cooked in every part and delicately imbued with the accompanying flavours. For once, we were able to eat fennel that was tender, tasty, juicy and green. Won over by the machine's uncanny prowess, my wife mused, "I suppose we could make room for one..."
Should we try these at home?
So what other gadgets could we filch from professional kitchens? Perhaps the biggest difference between the professional and the domestic kitchen is heat. The incomparable power of the professional oven explains why you cannot get the same results at home. A few manufacturers are now making ovens that produce professional heat. French-made Lacanche ovens (from £3,170-£12,050) are used at home by top professionals like Hugh Fearnley-Whittingstall, Rowley Leigh and Anton Edelmann. If you really want the profession touch, you should also go for the super-powerful electric grill known as a salamander (£1,290).
The thermoblender is a professional gadget that is appearing in a few domestic kitchens. It is a combination of blender/ kneader/liquidiser, with one significant difference: it contains a heating element, so you can also use it for making dishes such as hollandaise sauce, chicken liver parfait and lemon curd. It provides short cuts when making marmalade or custard. The only drawback is £800 price tag and, of course, how much you would use it.
Advocating the thermoblender on the Radio 4 Food Programme, Cyrus Todiwala of Café Spice Namaste said, "For soup, it is the best." But another, far cheaper gadget that started out in the professional kitchen does much the same job. The hand-held blender or stick blender has been used in professional kitchens, where it is known as the "outboard motor", since the Sixties. Much reduced in size, it came on the domestic market in the Eighties and is now available from around £6. I use mine at least once a day, often more. In my view, it works better than a blender for soup – quicker and less messy – at a fraction of the price.
We have also stolen the digital scales, meat thermometer and mandolin chopper from the professionals, though the accumulation of gadgetry reminds us of one major difference between us and them: their kitchens tend to be bigger.