An oven that combines convection and steam heat is proving to be an invaluable asset to chefs. Here's what you need to know to buy one.
Combining convection oven and steamer capabilities into a single cooking cavity has been one of the great foodservice innovations of the past quarter century. Other great cooking equipment innovations like the microwave oven and induction burner have changed restaurant kitchens, but no other piece of equipment can match the combi oven's productivity and versatility to do so many types of products well. If you don't have one yet, here are some items to consider.
The combi oven is a cooking unit that combines three modes of cooking in one oven — steam, circulated hot air or a combination of both. The steam mode is well suited for vegetables and shellfish. The hot-air mode operates as a regular convection oven for baking cookies, cakes and pastries. The combination mode is used to reheat foods and to roast or bake. The combi mode decreases overall cook times, reduces product shrinkage and eliminates flavor transfer when multiple items are cooked simultaneously.
Some models offer additional specialty modes using hot air and steam to defrost, rethermalize, poach or gently steam and warm. Many types of red meats and poultry products are well-adapted to combination cooking because they can be prepared so many ways.
The really great thing about a combi is that it can replace two pieces of equipment in the space of one. It takes up about half the area of a convection oven and a steamer. The space saved can translate into cost savings because you'll use less exhaust hood stainless steel, and three or four feet of reduction can represent a significant ongoing energy savings.
Despite the benefits of a combioven, it's still an expensive piece of equipment. But the good news is that lower cost combi ovens have entred the market. The newer type of combi is a boilerless unit. The expensive boiler in standard units is eliminated and the resulting steamer/ovens are about 15-20 percent less than the typically sized counterpart. The only drawback is slightly reduced steam output needed in high- volume fast cooking. In many applications the difference in the units is not noticeable.
An added benefit to the boilerless combi is reduced liming problems due to hard water. Over half of combi maintenance problems are due to excessive scale and lime buildup that can be eliminated in a boilerless model.
Combis range from countertop units to floor-mounted roll-in units for banquets or institutional use. The models most available are the four- to six- 12" × 20" pan-capacity countertop unit, a seven- to 10-pan unit and the larger floor or stand-mounted 14-, 18- and 20-pan models. The smaller units generally hold only a 12" × 20" pan or half-size baking pan. The larger units hold two 12" × 20" pans on each shelf or a single 18" × 26" baking pan.
All combi sizes and styles are generally available as electric units. Gas units are produced by some manufacturers, but they are usually more expensive than electric units and available only in certain sized models.
Generally the smaller units are only available for electric operation. If you are using an electric unit, be sure you have enough power to handle a fairly substantial load. For example, a 10 steam table pan-sized unit requires between 13 and 19 kilowatts to operate.
Be careful, because options will cost you thousands of dollars even in the small countertop models. Do consider a built-in spray hose for washing out the interior. Also consider a good water filter, which will slow mineral deposit buildup in the unit's water lines and elsewhere.
Other items to consider are enhancements in fan design for more even air movement. Another is a better self-cleaning option. A third to consider is a new model that offers microwave cooking energy that offers even more cooking speed.
Dan Bendall is a principal of FoodStrategy, a Maryland-based consulting firm specializing in planning foodservice facilities. He is also a member of Foodservice Consultants Society International. Bendall can be reached at 301-233-5226.

