Commercial Cooking

Why Design Electric?
As an engineer, why would you want to design electric kitchens? Here are a few reasons:

  • More flexibility on location
    • No combustion air requirement
    • Many electric appliances do not require ventilation hoods
  • Cooler kitchen
    • More heat goes into food rather than onto workers
    • No pilot lights
  • More comfortable dining room
    • Lower hood requirement means that less air is taken from adjacent dining area; reduces load on equipment serving adjacent areas
  • Very satisfied customers

Food Service Decision-Making
Methods of Heat Transfer
Cooking Principles
Energy in Foodservice

Commercial Cooking

The term foodservice applies to any operation or business that prepares food for consumption by the public. These businesses are classified into three main categories:

  • Quick Service - Commonly referred to as fast food restaurants. These include burger, chicken, pizza, sandwich, and short order restaurants where there is generally no table service. The kitchen and dining rooms are designed for quick service and convenience
  • Full Service - Commonly referred to as dinner house or white tablecloth restaurants. These include table service, sit-down cafeteria, club, and fine dining operations where there is more emphasis on ambiance or the dining experience
  • Noncommercial - These are foodservice operations that are generally imbedded in other businesses. They are generally found in schools, hospitals, universities, office parks, office buildings, prisons, and industries

Many commercial restaurants come and go with changing public desires. Restaurants generally concern themselves with only those things that can be seen by the public. They often consider used equipment and are not interested in high technology, energy-saving, or high first cost approaches to food production.

Production, productivity, and profitability are the key to any foodservice operations success. All of these operations have one thing in common; they are manufacturers of food and the tools of production. They use various pieces of cooking equipment. It should be pointed out that the purchase of advanced technologies is seen as a capital expenditure. Actually, advanced electrotechnologies are a revenue investment since they enhance the means of production.

Food Service Decision-Making

The complexity of the decision-making process in the fast food sector is a function of the type of ownership. There are two basic types of ownership.

  • The first type is the local owner/operator who owns and operates a single facility or very small chain (typically less than a six store operation). These owners are characterized by a deep personal involvement in their business and a high commitment to quality and service. They are also concerned about holding down costs, but not at the expense of quality. The decision-making process in this group is very straightforward: the local owner/operator is the decision maker.
  • The second type of ownership is the large chain with a local manager and possibly a franchise owner. The decision-making process is often more complex in this group since the decision maker is not at the local operations level. The institutional sector decision-making process also is complicated by the ownership factor, since the food service operation is frequently contracted out and the facility is owned by someone else. Therefore, the food service operators often work with equipment already installed at the facility.

Cooking equipment decisions in these situations are made by the facility owner/operator and head of engineering, as well as the food service contractor. In most cases, food service is only a small portion of the owner's expenses, and equipment replacement is only considered when it fails. The hotel/motel sector has complicated, multi-level decision-making processes. There may be as many as three to five decision makers involved in the selection of cooking equipment, including the hotel/motel general manager, the food and beverage manager, and the chef. In addition, the head of engineering and the operations manager of the chain may have input. The most straightforward decision-making process is the full-service sector, where a local owner is intimately involved in the operation. These individuals may have others who offer opinions, but the "buck" stops with the owner and so does the decision.

Methods of Heat Transfer

Commercial cooking establishments contain a variety of equipment with specialized functions; nevertheless, there are only a few basic cooking methods. These cooking methods can be further condensed to three basic heat transfer methods: conduction, convection, and radiation.

  • Conduction is heat transfer through a material or from one material to another in direct contact. An example of conduction is cooking something in a frying pan.
  • Convection uses heat transfer by movement of a gas or liquid. An oven cooks by convection. Air is heated which in turn heats the food.
  • Radiation heats by infrared waves. The broiler or a toaster cooks by radiation. Also, microwave ovens cook by electromagnetic waves.

Cooking Principles

Several cooking methods take advantage of more than one heat transfer principle.

  • Baking/Roasting
    Baking is a dry heat cooking method. Food is cooked by radiant heat transfer from the heating element and oven walls and by contact with heated air. Baking is a relatively slow cooking process.
  • Convection Baking
    Convection baking improves upon conventional baking through use of a fan to circulate warmed air around the food, improving the heat transfer process and shortening cooking times.
  • Broiling
    Broiled food is cooked by radiation on one or more sides. Broiling is usually performed in an open or semi-open environment.
  • Boiling
    Food in liquid is cooked by heating to the boiling point. Unpressurized boiling provides even cooking at the boiling point temperature (e.g., 212&F for pure water at sea level).
  • Frying
    In deep fat frying, food is immersed in hot cooking fat. Because the cooking medium is greater than 320&F the liquids that surround the food boil which in turn conducts heat to the center of the product. Frying imparts a texture change that is considered desirable.
  • Pan Frying or Griddling
    In a fry pan or on a griddle, food is cooked by conduction from a flat, heated surface at high temperatures. A small amount of cooking fat is used to prevent sticking. In the process, the food is caramelized.
  • Steam Cooking (Unpressurized or Vacuum)
    Steam is used for even, fast cooking. Usually, the steam is condensed on the food, transferring its heat energy. Because of its higher heat transfer coefficient, steam is more efficient than boiling water.
  • Steam Cooking (Pressurized)
    Pressurized steam cooking is a very fast, higher temperature method. The pressure in the vessel is controlled to the desired temperature above 212&F.
  • Microwave Cooking
    Microwaves generate electromagnetic energy that penetrates food, exciting water molecules to cause them to heat. Microwaves only penetrate the outer two inches of the food. Thick food cooks internally by heat conducted from the outer layers.

Energy in Foodservice

Energy represents less than 3% of a foodservice operations total expense. This percentage stays relatively the same in gas or all electric operations. For any savings that are found by cooking with gas, they are lost to increased cost of air conditioning.

Of the 3% cost of energy, the distribution of consumption is as follows:

Refrigeration 2/10¢
Lighting 4/10¢
Sanitation and Clean-up 5/10¢
Food Preparation 4/10¢
Cooking 7/10¢
HVAC 8/10¢

Other energy and utility considerations and key issues in foodservice are :

  • Type of foodservice facility (fast food, full service, institutional, etc.)
  • Type of food to be offered (general, ethnic, seafood, pizza, deli, gourmet, etc.)
  • Building construction and orientation
  • Occupant use and maximum occupancy (particularly time of day)
  • Time and seasonal value of fossil and electric energy to be used
  • Availability and price of water and sewage
  • Labor costs and retention
  • Equipment longevity and serviceability

Other Information

Links to related topics

Auxiliary Equipment

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