The Gastrovac - cook food at much lower temperatures and enhance flavour

For fans of sous-vide, the Gastrovac could represent the logical next step.

Self-confessed technophile Simon Rogan of L`Enclume tried it for himself

I first heard about the Gastrovac from visits to food conferences, like Fusion in Madrid, and I got quite excited about it. I discussed it with Tom Kerridge from the Hand and Flowers in Marlow. He didn`t want one; he`s a very good but quite traditional chef, whereas I am very much into food technology.

We`ve been using sous-vide techniques for some time now and it seemed to me that the Gastrovac might be the next logical step forward. The three main bits of kit we had already were the vacuum-packing machine, the temperature controlled water baths and the Hold-o-Mat, a Swiss-made, lowtemperature oven.

The two great features of the Gastrovac, as far as I was concerned, were the facility to boil or fry food at much lower temperatures than normal, and the potential to enhance flavour by releasing the vacuum and allowing the cooking liquid to flood back into the food, thereby replacing the oxygen that had originally been there.

I`m getting old now so I want to take as much heat out of the kitchen as possible. The new restaurant I`m opening in Henley later this year won`t have any gas at all, it`ll just have induction ovens, and we`re changing the stoves at L`Enclume too. Apart from anything else, it`s a much greener way to run a kitchen.

I managed to get a Gastrovac on loan from the UK distributor a couple of weeks ago, just to try it out and play around with it. I am a real technophile and my mind was racing with the possibilities of what I could do with it.

Then it arrived.

I found it very frustrating and, for the first few days, I just scowled at it. It is a very complex machine to use and I really couldn`t get the hang of it at all.

For a start, there are so many variables. Not just time and temperature, but the percentage of vacuum: the Gastrovac can go up to 90 per cent. We had already laboriously compiled lists of the correct times and temperatures for our sousvide dishes; now, with the Gastrovac, we had to start all over again. It really rips up the rulebook. The problem was that nothing we tried really worked, or at least, it didn`t do anything that we couldn`t already do using our existing kit.

But I soon realised that I`d charged at it like a bull at a gate. Part of the problem was that the recipes that came with the machine, from some of the Spanish chefs who have been pioneering the Gastrovac, were pretty rubbish. The only thing that seemed to work was infusing langoustines with a langoustine stock.

The trick was to mix the stock with methylcellulose – to plump them up a bit – and to turn the vacuum on and off every five minutes for an hour.

The langoustines turned out to be very well flavoured, with a good texture.

Having thought about it for a while, though, things started to work. I realised that I needed to start with things that had the right degree of porosity: I infused an apple with lovage, for example, which worked really well.

One thing I didn`t really expect from a machine costing more than £2,000 is that you have to hold the lid down when you use it. One version has a stainless steel lid, which clamps down, but mine just has a transparent lid and you need to keep it pressed down until the vacuum kicks in.

It`s very good at cooking poultry, though. We do a dish of squab cooked sous-vide, but the shrink-wrapping tends to contort the structure of the breast. I tried it in the Gastrovac, cut cooking time by 10 minutes and it was perfect.

I also managed to infuse the flesh with a light hazelnut and liquorice stock, which I couldn`t have done before.

At the moment I`m experimenting with it to do tempura and beignets, which is showing really promising results. The conventional tempura method can be a problem, because sometimes you need to overcook the vegetables or seafood in order to get the batter really crisp. Frying at a much lower temperature seems to solve the problem. My eventual aim is to do beignets of ice cream balls, with crisp, hot batter and frozen ice cream inside.

Meringues are fun too. I baked some soft meringues in dariole moulds and expanded them in the Gastrovac, letting the pressure back in just before they collapsed. I am also experimenting with rice crackers, frying them in a vacuum so that they can really puff up.

We`ll definitely buy one.

It wouldn`t suit anybody who likes instant results: it`s too difficult and complex to figure out straight away. It`s not like the Pacojet, for example, which takes a week or so to master.

The Gastrovac will take forever, because there are so many possible applications.

Nor will it replace the waterbaths and vac-packing that we do already. It`s not an all-singing, all-dancing machine and you shouldn`t expect it to do everything.

If you are stubborn and determined, though, like me, then it is definitely worth the investment, if only because it promotes curiosity about food and cooking techniques. My chefs turn up for work these days scratching their heads and saying, "What if we tried ?"

which is great.

In other words, I`ve seen the future. And it works. Sort of.

The Gastrovac is manufactured in Spain and imported and distributed in the UK by Magrini Limited, Unit 5, Maybrook Industrial Estate, Brownhills, Walsall, West Midlands, WS8 7DG, 01543 375311 magrini.co.uk