A cooking utensil is either a vessel in which foods are
cooked or a tool used in food preparation.
Here are some of the factors that should be considered when purchasing cookware or bakeware:
- Cooking utensils with flat bottoms, or
ones with concave bottoms designed to flatten on heating, straight sides
and snug-fitting covers are more efficient in the use of energy than other
shapes; heat enters the pan directly and is retained.
- Any flat-bottomed, warp-free utensils
may be used on many of the smooth-surface, ceramic-glass cooking tops;
check the range manufacturer's instructions.
- Utensils should be durable enough to
withstand daily use.
- They should be made of a material that
will not affect the color, flavor or nutritive values of the food being
cooked.
- Knobs and handles should be made of a
sturdy, heat-resistant material preferably with a flame or heat guard for
cool handling, strong enough to support the weight of the utensil when it
is filled, and should be securely attached.
- Cooking utensils should be tipping
whether full or empty.
- Construction and finish should make
utensils easy to clean. There should be no interior seams, crevices or
rough edges to harbor food or bacteria.
- Buy the best quality your budget will
allow, because most utensils are used frequently and should last for
years. Carefully read all labels, tags and manufacturer's pamphlets for
construction, use and care information. File these instructions for future
reference.
- Appearance-color, style and finish –
should be pleasing.
- Versatile sizes should be selected to
accommodate many cooking tasks. Use small pans for small quantities and
larger pans for larger quantities of food. Top-of-range utensils are often
sold in sets comprising the most common sizes; sets may be less expensive
than the same utensils purchased individually.
A Very Brief History of Cooking and Cookware
Cooking utensils have been with us almost since men discovered that raw food could be improved by exposing it to heat - cooking it.
The first cooking utensil may have been a hot flat stone, upon which meat could be placed in a fire. A close second was the spit or skewer, which held food away from direct contact with the fire and prevented its burning. When simple cooking vessels made from hollowed stone, pottery, or metal were invented, it became possible to cook by simmering, stewing, frying, and even baking, as well as roasting.
For thousands of years, common cooking utensils have been made of metal. In fact, one of the first uses of metal by man was from cooking utensils. Today, cooks may choose from a wide variety of cookware materials. Metals include aluminum, stainless steel, cast iron, stainless steel combined with other metals such as copper, aluminum, tin, or chrome and porcelain enamel or organic coated steel, iron and aluminum.
Like metal cookware, ceramic cookware has been available
for many centuries. In this century, heat resistant glass-ceramic cooking
utensils have been developed. Also, with increased popularity of microwave
cooking, plastic materials have developed totally new and unique shapes for
ovenware.
Whatever kind of utensil is used, heat is transferred from a heat source to a food mass. Although the principles of heat transfer remain constant, how well heat is spread is determined by the inherent thermal conductivity of a utensil, the finish on the utensil and the construction of a utensil. It is all important to select kitchenware with these factors in mind. Microwave cooking is less affected by these considerations.
Cooking Processes
Following are five processes by which heat is transferred, They are: conduction, convection, induction and radiation, plus microwave energy.
CONDUCTION - transfer of heat from the heat source directly to the utensil. The heat spreads across the bottom and is conducted up the sides of the pan. Heat is transferred directly to the food mass as the utensil heats. For conduction to take place, there must be some direct contact between the heat source and the utensil. Top of range utensils heat by conduction, so it is important to select those made of good heat-conducting material. There is limited conduction in oven baking because the baking vessel has little direct contact with the heat source.
CONVECTION - heat transfer by convection requires the movement of air liquids called convection currents. In the heating process convection modifies or controls the rate of heat conduction. Heat transfer is never by convection alone. In a saucepan, the fluid first begins to heat by conduction. Then the heated portion rises by convection and is replaced by the cooler portion. As the hot and cool food particles intermingle, the food mass uniformly warms.
Similar to surface cooking, when oven baking, air near the heat source rises and circulates, only to be replaced by the cooler air. The heated air, moving in convection currents, penetrates the food assisting the cooking process.
INDUCTION - heat is induced into the cookware, not transferred to it by the cook-top. An electromagnetic coil beneath a ceramic cooking surface creates a magnetic field. This magnetic field passes through the cooking surface to ferrous (iron or steel) cookware, heating the pan and cooking the contents. This cookware must have magnetic properties.
Non-magnetic metal such as aluminum cannot be used on induction ranges. The only heat generated is in the cooking utensil itself, as the cooktop remains relatively cool.
The induction unit is extremely energy efficient since almost no heat or energy is wasted beyond the edge of the pan and because heating stops when the pan is removed.
RADIATION - transfer of heat by electromagnetic waves. Radiation does not require direct contact with a heat source, liquids or air. Like sound and light, radiation is emitted in waves. The heat source in a broiler or an oven produces heat waves. These heat waves are radiated to the food mass thus penetrating and heating.
In a heated oven, over half of the heat is radiant energy. The transfer of radiant heat relies on the ability of a utensil to absorb radiant heat energy. Dark or blackened surfaces soak up radiant heat, while shiny, bright surfaces reflect heat. The food mass is baked by a combination of convection, radiation and some conduction.
MICROWAVE - heat transmitted by electromagnetic waves for cooking. Microwaves are very short in length and are produced by a special generator in the oven called a magnetron. These waves are then distributed by a stirrer or in some ovens, the food moves on a revolving shelf. Microwaves are sources of energy, not heat. When these waves are absorbed into moist food, the energy is transformed into heat and bakes and roasts food. Microwaves penetrate 3\4 to 2 inches into the food, cooking from the outside to the inside on all surfaces.
Microwaves reflect from all the metallic walls in the oven and penetrate the food from all angles, passing directly through the utensil. For this reason, glass, ceramic, plastic and paper are used as cooking utensils in microwave ovens. Metallic utensils reflect the microwaves away from the food. Some microwave cookware contains a safe combination of plastic and metal to give controlled cooking.
