PERFECT: Some users say their best baked pastries and rolls come from their combi oven.
SPACE SAVER: A combination oven can take up as little as half the area of a convection oven and steamer.
If you ask a cook what the most productive piece of cooking equipment in their kitchen is, many will point to their combination oven/steamer. The combination oven/steamer is a piece of equipment that can bake and roast like a convection oven; steam and poach like a steamer; and reheat or cook product without drying it out.
Most users claim an oven/steamer can do everything either a steamer or a convection oven can do and, in many cases, do it better than either as many operators are discovering. The combi can operate in any one of three operating modes:
- Steam only - The equipment operates like a pressureless steamer cooking at 212°F.
- Convection heat - The units works by circulating hot air with a range of temperatures generally up to typical convection oven temperatures.
- Combination steam and hot air - The combination mode works to typically provide faster cooking than dry heat alone while limiting shrinkage and still browning.
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. Steaming vegetables and fish, of course, is easily done. Some users say their best baked pastries and rolls come from their unit.
The steamer/oven operation mixes forced air convection for even browning, along with steam for moist heat to reduce product drying. The combination mode is especially suited for producing less shrinkage in meats than typical ovens. Breads and rolls baked in the combi mode will be fluffier and have more oven spring than those baked in traditional ovens. Rethermalizing leftovers and heating prepackaged frozen convenience foods also works well in the combi mode to reduce drying and over-browning.
There are other reasons to use the equipment. The combination oven/steamer can save space. Space is the ultimate premium in many operations these days. The combi takes up about half the area of a convection oven and steamer. The space saved can translate into cost savings, as well.
Using less stainless steel for the exhaust hood on a combi unit can represent a significant ongoing energy cost. Nevertheless, the typical combi is still expensive. Several manufacturers have engineered and are about to introduce an economy line of combi ovens that will appeal to the operation on a budget.
The boilerless combi
The new item is the boilerless combi. The expensive boiler is eliminated and the resulting steamer/ovens cost about 15-20% less than the typically sized counterpart. The only drawback is slightly reduced steam output needed in high-volume fast cooking. If you are doing slow roasting, the difference in the units should not be noticeable. Manufacturers hope these new boilerless units will open an additional market for combi ovens.
Oven/steamers on today's market range from small volume countertop units to floor-mounted, roll-in units with large capacities for banquets or institutional use. Typical sizes are stated by manufacturers in standard steamtable pan (12"x20") or baking sheet pan (18"x26") capacities. Note that shallow 2" pans are typically used in the sizing ratings. You will need to reduce capacity accordingly if using 4" or 6" pans that would be most typical for casserole items or lasagna.
Most manufacturers make several of the more popular oven sizes used in restaurants. The models most available are the four to six 12" x 20" pan capacity countertop unit; a seven-to ten-pan unit and the larger floor or stand-mounted 14, 18, and 20 pan models. The smaller units generally hold only a 12" x 20" pan or half-size baking pan. The larger units hold two 12" x 20" pans on each shelf or a single 18" x 26" baking pan. At least one manufacturer makes a specialized rotisserie combi great for displaying and cooking rotisserie-style chicken or other products. The unit can also be converted to traditional shelves for cooking other products.
Once the necessary size unit for your operation is determined, a primary consideration is whether the combi is to be for gas or electric operation. All sizes and styles are generally available as electric units. Some manufacturers produce gas units. However, they are usually more expensive than electric units and available only in certain-sized models. Generally, the smaller units are only supplied for electric operation. If you are using an electric unit, be sure to have enough power because they generally require a fairly substantial load. For example, a ten-steam-table-pan unit requires between 13 and 19 kilowatts to operate.
Water quality is vital
As with all steam equipment, the quality of water going into the combi is of utmost importance for good equipment performance. The majority of all service problems with combis are related to liming or mineral deposit build-up. Most manufacturers recommend a water filter for the equipment. Have your tap water tested for hardness and use filters to correct the level to within the standards the manufacturers' recommend,
You can't be complacent just because you have a water filter. Along with water filters, consider also a regular program for manual or automatic deliming. Some of the full-featured ovens have an automatic deliming program that automatically recognizes when to delime. When activated, the combi then goes into a deliming cycle using chemicals supplied to a special reservoir on the unit.
The combination mode is especially suited for producing less shrinkage in meats and fluffier breads and rolls.
When selecting equipment, you also need to consider several options. Many manufacturers have multiple lines of combis, from basic to deluxe with varying amounts of programmability or other options. Look carefully and buy the options you need, but don't over-buy as step ups in features are generally several thousands of dollars even in the small counter-top models. The newer boilerless combis will generally be made for the budget-conscious and have less frills than some ovens.
Most units are fully stainless steel inside and out with a glass window. They are generally easy to clean, although several models have a built-in spray hose for washing out the interiors. Meat probes are not standard with some units and should be purchased, especially if a lot of meat roasting is planned. The probes are integrated into the computerized controls to provide consistent product every time you use the unit.
One important, but often overlooked operational consideration is a side shield required on some units. The side shield is used when the oven/steamer is next to other cooking appliances to prevent the item's electrical controls from getting overheated. The solid state and computerized controls are very sensitive to heat and can easily be damaged if in the vicinity of a range or broiler.
Nearly all types of foodservice operations can benefit from having a combination oven, from small limited-service outlets to large mass feeders, from upscale dinner houses to convenience food snack bars. Wide acceptance among cooks and clear advantages in food preparation have made the combi oven an expected item in the modern kitchen and one that earns its accolades.
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 (FCSI).