Combi-ovens

A combi-steamer or combi-oven, as it is often called, is, in fact, four ovens in one. First, it is a normal convection oven for baking and roasting, with heat from either gas or electric elements forced around the oven cavity by fans. It's also a pressureless steamer, able to cook delicate foods such as fish and green vegetables. These two functions can be combined to cook with heat and moisture in the air. The fourth function is as a regeneration oven, to heat up chilled or precooked food without drying out or losing colour or taste.

There is nothing that sounds complicated in that description, but a combi-oven is, nevertheless, the most sophisticated piece of cooking equipment you can find in a kitchen. After all, it involves a combination of water, electricity or gas heating and computer microprocessors.

So complex are combi-ovens that, while there are more than 60 brands on the market, there are few manufacturers. There is almost no combi-oven production outside Europe.

Specialist knowledge

Yet this is a plus point in combi-ovens: being built by companies specialising in the technology means their performance and reliability will be better. So what questions should be asked on the combi-oven stands at Hotelympia?

The first point to cover is the cooking needs of your establishment. Salesmen will not admit it, but there are a lot of unnecessary combi-oven purchases made. Where kitchens go wrong is to pick an expensive combi-oven to perform a job that could be met by a much cheaper, single-function oven.

If there is a lot of steaming to be done, it makes better economic sense to buy a dedicated steamer. Similarly, if there is a lot of baking to be done, buy a good convection oven.

Of all the features a combi-oven offers, roasting meat is the most beneficial. The blown hot air cooks items such as beef and chicken, while the addition of injected steam keeps food moist, preventing it from drying out. Meat can lose up to 30% of its carcass weight during dry-roasting, with obvious food-cost implications.

The injection of steam into the oven cavity is the principle of the combi-oven, and there are two design concepts for doing this. In northern Europe the preferred method is having a steam-generating integral water boiler. In southern Europe the popular system involves spraying water on to the heating elements to generate steam.

There is an ongoing debate about which system is best, but the most common argument against spray-on steam systems is that they are more inclined to maintenance problems and can leave water deposits in the oven cavity. The argument against steam boilers is that they add expense and create maintenance problems.