ALUMINUM COOKWARE
Properties Of Aluminum Cookware
One of the reasons aluminum cookware is so popular is
that it is an excellent conductor of heat. Because of this quality, heat
spreads quickly and evenly across the bottom, up the sides and across the cover
to completely surround the food being cooked. This is one of the
reasons why many leading food manufacturers are packaging convenience and
frozen foods in disposable aluminum containers.
Relatively, aluminum is a lightweight metal, a property
that makes it very useful for building aircraft. In the kitchen, it means that
a sturdy aluminum pan is also easy to handle, since it is lightweight for its
size.
Aluminum is also the third most abundant element in the
earth's crust. In nature, aluminum is always found in combination with other
materials. An ore called bauxite is our most common source of the metal.
Bauxite contains a greater percentage of aluminum than do ores, and the metal
can be extracted more economically.
Some people are surprised to learn that they ingest trace
amounts of aluminum virtually every day of their lives. It's because aluminum
is so abundant in soil that plants naturally absorb it as they grow. Likewise,
animals which are raised for food absorb traces of aluminum from their feed.
The use of aluminum cooking utensils has been subject to
notions that it is harmful to health. Aluminum occurs naturally in the human
body, on the average, a content of 300mg. FDA studies indicate that the
ingestion, if any, aluminum into the body from aluminum cookware is so minute,
that there are no adverse health effects.
A study at the University of Wisconsin determined that only 2.5mg of aluminum per day will be typically added to the diet from this source, if all cooking and food handling is done with aluminum products. It is doubtful that even a portion of this amount becomes biologically available; most, if not all, passes naturally out of the body. There are many other sources of aluminum ingestion far greater than that from aluminum cookware that are equally harmless to the human body, such as over-the counter medications.
Manufacturing
Aluminum cookware is manufactured principally by the
following methods: stamping, drawing and casting.
Stamping or Drawing:
In the stamping and drawing method, flat sheets or circles of metal rolled to
the desired thickness are placed on a press. The press then forms the sheet
metal into the desired shape.
Afterward, the finishes are applied, both inside and
outside, and appropriate handles and knob attached.
Casting:
Molten aluminum is poured into specially designed molds for each different
cookware unit. The molds for casting allow the thickness of the cookware to be
strategically varied to those areas of the pan for maximum cooking efficiency.
For example, the pan bottoms can be made extra thick for
superior heat absorption and the panwalls can be slightly tapered to create a
circular heat movement up and around the pan. When the aluminum cools, the mold
is opened and the cookware removed.
Cast aluminum utensils tend to be heavier and thicker than stamped. The bodies of all aluminum utensils are made in one piece so that there are no seams or hard-to-clean crevices.
Generally, the gauge or thickness of the aluminum utensil is one feature determines its quality. The heavier the gauge (thickness), the more durable and more costly the utensil. For this reason, the intended use of a utensil should always be considered when
purchasing.
Gauge is usually described by a number, the smaller number, the thicker the aluminum. For example, eight (8) gauge aluminum is thick (. 125 inch); twenty (20) gauge aluminum is thin (.032 inch).
Finishes
Aluminum utensils are manufactured with a wide variety of
finishes. Stamped and drawn utensils may have exterior finishes of polished
natural aluminum, chrome plate, anodized (with or without color), porcelain
enamel coating, nonstick coatings, or colored organic coatings (acrylics,
polyamides, etc.). Usually bottoms have a satin finish or are porcelain enamel
coated; both finishes help absorb heat.
Cast aluminum cookware may have exterior finishes of
colored porcelain enamel coating, polished, hammered or velva-glazed natural
surfaces, colored organic coating, or hard-coat anodized surfaces. The inside
finish on aluminum utensils may be a natural finish, "sunray" or
"spun" high polish finish, hard-coat anodized finish or nonstick
coating.
Use And Care of Aluminum Cookware
New aluminum utensils require washing in warm sudsy water to remove manufacturing oils. After use, aluminum utensils, like most cookware, should be allowed to cool before washing or soaking. This is a simple safeguard against warping, as well as preventing accidental bumps in handling. Drying immediately after washing will help preserve their appearance. Wash them each time they are used.
Undissolved salt allowed to remain on an aluminum surface may cause pitting. Add salt to liquid after it reaches the boiling point and stir to dissolve it completely. Do not allow acid or salty foods to remain in aluminum-finished utensils for long periods of time, because this may cause pitting.
Because it combines easily with other natural elements,
aluminum may stain when it contacts minerals in water and in foods.
Automatic dishwashing may increase the amount of staining
when the high heat of the drying cycle is added to minerals naturally present
in water and the chemicals used to purify water. For that reason, hand washing
may be preferred to preserve the attractive finish of aluminum utensils.
Utensils with coated exteriors and interiors may be
washed in automatic dishwashers. However, care should be taker when loading
them into the dishwasher to avoid marring or scratching the coating.
To remove food which may have accidentally burned on
inside a utensil, fill the pan with water to cover the burned food and simmer
over low heat until particles loosen, occasionally scraping burned particles
with a wooden spoon. After simmering, scour, wash normally, rinse in hot water
and dry.
Stains and discolorations that may appear on aluminum
utensils can be removed by boiling a solution of two to three tablespoons of
cream of tartar, lemon juice or vinegar to each quart of water in the utensil
for five to ten minutes. Then lightly scour with a soap-filled scouring pad.
Cooking acid foods such as tomatoes or rhubarb will
remove the stains naturally without affecting the cooked food product.
To remove stains from the aluminum exterior, use
nonabrasive cleanser. Cooking tools made of wood, plastic or smooth-edged metal
are recommended for use in aluminum utensils. Sharp-edged tools such as knives,
mashers and beaters may scratch aluminum.
STAINLESS STEEL COOKWARE
Properties Of Stainless Steel Cookware
Stainless steel cookware and bakeware is exceptionally
durable. Once stainless steel has been stamped, spun, or formed into utensil
shape, it takes an extremely hard blow to dent it. Its attractive finish won't
corrode or tarnish permanently, and its hard, tough, non-porous surface is
resistant to wear. Extremely smooth and scratch resistant, stainless steel
utensils take an excellent polish.
Stainless steel is one of today's most glamorous,
versatile and useful metals. It is used virtually everywhere - in space ... on
the exteriors of skyscrapers ... throughout industry ... and, just as
important, in millions of kitchens where top-of-range cookware, bakeware,
pantryware, tools and other equipment ease the work of homemakers.
Like other steels, stainless steel is an alloy-a
combination of iron and other metals. What makes it different from other
steels, however, is that it contains at least 11 percent chromium. It is the
chromium that makes the steel stainless all the way through.
Stainless steel may also contain other elements, such as
nickel, molybdenum, columbium, or titanium. These materials can contribute special
hardness, high temperature resistance, and resistance to scratching and
corrosion to the finished stainless steel alloy.
Manufacturing
Stainless steel bakeware usually is fabricated of solid
stainless steel. On the other hand, top-of-range stainless steel utensils are
generally made by combining stainless with other metals, usually aluminum, copper or
carbon steel. The other metals improve the utensil's heat conductivity.
Various manufacturing processes are used to combine
stainless steel with these other metals. The resulting combinations are
described as two-ply, three-ply, bottom clad, three-ply/bottom clad, and
five-ply/bottom clad and five-ply.
Two-ply cookware commonly have stainless steel interiors with another metal on the exterior. In a few
instances, this arrangement is reversed, with the stainless steel on the
outside.
Three-ply cookware have
stainless steel on both the inside and outside surfaces with a layer of copper,
carbon steel, or aluminum forming the core.
Bottom clad utensils are formed with solid stainless or
three-ply, and copper is plated to the bottom or aluminum is applied to the
bottom by casting, bonding or metal spraying.
Five-ply/bottom clad utensils are made by the three-ply
process, with two clad layers on the bottom. Five-ply utensils are made with
stainless steel on both the inside and outside surfaces with three layers of aluminum
or other metals forming the core.
In the actual manufacture of stainless steel cookware,
the metal's versatility permits it to be formed into a wide variety of
attractive and functional shapes, limited only by the imagination of the designer or the desires
of the
consumer.
Finishes
Appearance is an important consideration in the selection
of cooking utensils. A choice of high polish or satin finish is normally
available on stainless steel cookware. Either of these attractive finishes
blends well with all colors and periods of kitchen décor.
Also, to meet decorator demand for color in cookware,
manufacturers are producing cookware with porcelain enamel exteriors on
stainless steel. But the cooking surface is always stainless steel, where case
of cleaning and protection of food quality are most important.
Use and Care
Before using a new stainless steel utensil, check the
manufacturer's tags and labels for special tips on use and care. Wash the
utensil thoroughly in hot sudsy water to remove manufacturing oils and
polishing compounds.
Stainless steel is one of the easiest materials to clean
and keep clean. Washing by hand in hot sudsy water or in a dishwasher usually
is the only requirement for keeping stainless utensils bright and shiny. Prompt
drying prevents water spots.
To remove burned-on foods, soak and wash in hot sudsy
water. Light scouring with a non-abrasive household cleaner and a nylon
scouring pad or a commercial stainless steel cleaner will remove stubborn bums
on the interior surfaces.
High heat may cause a mottled, rainbow-like discoloration
commonly called "heat tint". Cooking certain starchy foods-such as
rice, potatoes, or peas-may cause a stain on the inside of the pan. Both of
these can be removed easily with any one of a number of readily stainless steel
cleaners.
Undissolved salt will "pit" steel surfaces. Add
salt to liquid after it reaches the boiling point and stir to dissolve it
completely. Do not allow acid or salty foods to remain in stainless steel for
long periods of time.
With normal use, stainless steel cookware will not dent,
warp, or chip. It thrives on exposure to air, so it is an attractive utensil to display in the
kitchen.
COPPER COOKWARE
Properties Of Copper Cookware
Copper, alone or in an alloyed form, has been used in
cooking utensils almost since the dawn of history. Copper's uniform heat
conductivity makes it a good material for top-of-range cooking because the heat
is distributed evenly. This property also enables copper serving utensils to keep foods palatable.
Copper cooking surfaces are usually lined with tin,
stainless steel or coated with a nonstick finish because cooked foods left
directly in contact with uncoated copper may become discolored. While it is not
necessarily injurious to health, the discoloration tends to detract from the
food's eye appeal.
An electrolytic process that deposits copper on the
bottom of a stainless steel utensil utilizes copper's superior heat
distributions. Another manufacturing process bonds or laminates copper to
stainless steel or other metals. A core of solid copper sandwiched between two
layers of stainless steel is another way copper is used to distribute heat
uniformly.
Use And Care
Copper can be easily polished with various commercial
copper cleaners. A mixture of flour, salt, lemon juice and ammonia or a mixture
of vinegar and flour are two methods of keeping copper utensils shiny.
After cleaning, wash in sudsy water and rinse before
polishing with a soft, clean cloth. Tin
linings may wear off with frequent use; the utensil can be retinned.
CAST IRON COOKWARE
Properties of Cast Iron Cookware
Cast iron utensils have been with us for thousands of years. The Chinese apparently were the first to use them, producing cast iron
bowls in which to cook and eat rice. That was nearly 3000 years ago.
In Europe during the Middle Ages, cast iron utensils were considered so valuable that they were listed along with gold, jewels, and other riches of royalty. An iron foundry, where utensils and other cast iron products were manufactured, was one of the first industries organized in North America.
Today's cast iron cookware has improved greatly over those of even the recent past. They are made of iron alloys that give additional strength to the utensil. And today there are cast iron utensils with colorful porcelain enamel exterior and interior finishes.
Cast iron currently is used for utensils that include
skillets, roasters and Dutch ovens, broilers, griddles, and some specialty
items, such as muffin and corn bread pans. These utensils are excellent for
browning, frying, stewing and baking foods.
Use and Care
Natural cast iron utensils benefit from slightly
different handling in the home that the techniques recommended for other
materials.
For one thing, natural cast iron usually is
"pre-seasoned". It should not be washed with strong detergents or scoured.
Instead, hot sudsy water may be used, and the utensil rinsed and wiped dry
immediately.
The inside of the washed and dried utensil should
frequently be coated with unsalted cooking oil or shortening, just before using
again, it should be wiped with a dry cloth or paper towel.
Never store a natural cast iron utensil with the cover on, as this might cause sweating and consequent rust damage. Store these utensils in a dry place.
Natural cast iron utensils can be re-seasoned if necessary. This is done by scouring the utensil thoroughly, washing it in soap and water and drying it, and then coating the inside surface with unsalted cooking oil or shortening. Then the utensil should be heated in a moderate oven for about two hours. When the utensil is removed from the oven, excess grease should be wiped away.
Cast iron utensils with porcelain enamel interiors do not need seasoning. Hot sudsy water and thorough rinsing will keep them clean and shining.
TIN COOKWARE
Properties of Tin Cookware
The genealogy of tinplate in the kitchen can be traced to
ancient times. Tin was widely used in Egypt, although it was not found
there. Daring Phoenician sailors ventured to the British Isles, then known as the
Cassiterides or Isles of Tin, to obtain this precious metal.
Tin plating-the process of plunging plates of iron into
molten tin-was invented in Germany during the 16th century. The
secret of using as a protective coating for metal was brought to England about 1670.
In our age of new concepts in material and fabricating
methods, tin-plated steel still plays an Important role, particularly
in the baking industry. Many commercial baking utensils are made from
tin-plated steel because it is durable and possesses excellent inherent baking
qualities.
The consumer market for this type of merchandise has also
been important over the years to bakeware sales because of the utensil's
economy and baking qualities.
Very little care is required in using tin-plated
bakeware. This steel-based material is highly resistant to denting and
scratching. Tinplate provides the necessary protection that helps the steel
resist rusting and staining.
PORCELAIN ON METAL COOKWARE
Properties of Porcelain On Metal Cookware
Porcelain enamel on metal has served the needs of mankind
for centuries. The exact time and place of its origin are not known, but
measures throughout the world contain many examples that predated the birth of
Christ. These ancient artifacts remain as bright, clean and well defined as the
day they were created.
Originally porcelain enamel was an artistic medium for
making fine jewelry and, even when it was used to make a functional object such
as an urn or small box, it was invariably fashioned in
painstaking, handcrafted designs. For centuries porcelain enameling developed
as an art form, with only gold, silver, copper and bronze used as its base
metal.
Then, in 1830, a Bohemian craftsman found he could create
a permanent, smooth, glossy surface on cast iron by dusting the red-hot metal
with dry, powdered porcelain-and a new era dawned. From that time on, porcelain
enamel became a utilitarian as well as a decorative finish.
Porcelain enamel is essentially a highly durable glass,
which, with coloring oxides and other inorganic materials, is fused to metal at
extremely high temperatures. It first found its way into the kitchen as a
decorative finish for wood-burning ranges and cast iron utensils. Later, when
techniques were discovered for applying it to sheet steel, it became a standard
coating for coffee pots, roasting pans, and saucepans.
Manufacturing
In the manufacture of cooking utensils, porcelain enamel
is applied after the metal is formed into its final shape. It can be applied to carbon steel,
aluminum, stainless steel, and cast iron.
It is one of the most versatile finishes, offering
virtually an unlimited range of colors and design effects. Today's colors
include many shades of bright reds, vibrant greens, clear blues, sunny yellows,
and warm oranges, as well as earth tones. Plaids, stripes, decorator designs,
and even provincial prints can be found. There are also decorative porcelain
decals, mechanically applied that have the same scratch and stain resistant
qualities of the regular porcelain coating.
Use and Care
Aside from the variety of colors and designs available, the
chief recommendations for porcelain enamel are its stain and scratch
resistance, its immunity to fading and peeling, its chemical resistance, and
the fact that it will not pick up food odors.
Porcelain enamel utensils can be used for cooking,
baking, serving and storing food. Do not use porcelain enamel utensils over
high heat for a prolonged time; extreme high temperatures may cause the
porcelain to melt.
Cleaning porcelain enamel is easy. Just wash in warm
sudsy water, using a sponge or cloth. Burned-on foods or other stubborn stains
can be removed by soaking or by using a non-abrasive cleanser and nylon or
other non-abrasive scrubber.
All porcelain enamel cookware that have a nonstick finish
applied to the interior surface are safe in modern dishwashers.
GLASS, CERAMIC AND GLASS-CERAMIC COOKWARE
In the 20th century, heat-resistant glass and glass-ceramic were developed. Like ceramic, they meet the need for attractive ware used for mixing, cooking, serving, and storing.
Major features are attractiveness, one-dish convenience, and inert non-porous surfaces that won't absorb food odors or flavors. For easy cleaning, both glass and ceramic ovenware are available with nonstick interiors.
While most are very rugged, they can break under impact. However, some glass, ceramic and glass-ceramic cookware manufacturers warranty their products against thermal breakage, and offer free replacement should the ware break in normal use within the warranty conditions.
Heat-resistant glass cookware may be made of clear or tinted transparent material or opaque white (commonly called "opal" glass). Glass-ceramic cookware may be white or transparent and tinted. Ceramic cookware is available in white or a variety of colors.
Properties of
Glass, Ceramic And Glass-Ceramic Cookware
Heat resistant glass can be used for storing, cooking and
serving. Some pieces can be used on the rangetop, while others are suitable
only for the oven. Those designed for baking can be taken from refrigerator and
put into preheated ovens after the utensil reaches room temperature.
As a rule, they should not be used on the range top or
under the broiler. Heat-resistant glass range top products should always be
used with a wire grid on an electric range but should never be taken from the
refrigerator or freezer and placed directly on a hot range top element.
Similarly sudden cooling may be harmful to glass
cookware. Hot glass cookware should not be allowed to come in contact with wet
countertops, nor should they be placed in water while they are still hot.
Some ceramic cookware is made of heat-resistant material,
which can go from the freezer to a hot oven or microwave. None is suitable for
top-of-range or broiler use.
Like glass cookware, ceramic cookware holds heat for a
long time while providing the additional benefit of an attractive serving dish.
Ceramic cookware is available in a wide variety of shapes, colors, and designs.
Among the most thermally shock-resistant material ever
developed by man, glass-ceramic is a true space-age material. It was first used
in rocket nosecones because the glass-ceramic material could take the extreme
temperature changes encountered in their supersonic flight from the earth's
surface into outer space and back.
Glass-ceramic cookware offers wide food preparation
versatility. It can be used for rangetop cooking and is excellent for roasting,
broiling or baking -in the conventional or microwave oven. It can go directly
from the freezer to the rangetop, broiler or hot oven. Glass-ceramic cookware
can be immersed, hot off the stove, into sudsy dishwater for easy cleanup.
Manufacturing
Glass is a non-crystalline material manufactured by
melting a combination of raw materials including sand, soda ash, limestone,
feldspar and borax. The glass used in cookware is normally melted in a large
refractory furnace or tank at temperatures exceeding 2000 F.
A small portion of the molten glass is drawn out of the
tank and is blown or pressed in a mold. The mold essentially cools the glass
causing it to solidify. Following forming, the glass article is cooled to room
temperature on a schedule specifically designed to insure development of the desired
heat-resistant characteristics.
A glass-ceramic is a special glass composition, which is
melted and formed like heat-resistant glass. Following forming, the glass
articles are subjected to a special heat-treating schedule resulting in the
development of a fine crystalline structure throughout the article. It is
crystalline structure (which may be transparent or opaque) that gives the
glass-ceramic its unique performance characteristics.
Ceramic cookware is manufactures from a mixture of water,
clays, fluxing minerals (often feldspar) and finely ground sand. The particular
forming method used depends largely on the water content of the mixture. A high water content (relatively liquid solution) permits
casting of the ware in a mold. A lower water content
results in a plastic mass, which can be forced into the desired shape by a
variety of methods.
After forming, the ware is dried and fired (subjected to
temperatures in excess of 2000 F.) in a ceramic kiln to bond the components of
the "body" together. Following this initial firing, the surface of
the ware is coated with a glaze which, upon firing in a second ceramic kiln,
develops a smooth non-ceramic cookware with a nonstick
interiors three layers of nonstick coating are applied to specially
prepared interior surfaces and then cured at approximately 800 F.
Use and Care
Ceramic, glass and glass-ceramic materials are excellent
retainers of heat. Baking dishes and casseroles made of these
materials hold the food's heat long after it is removed from the oven. It is
usually recommended to use these items at slightly lower temperatures for a
shorter length of time because the covered cookware continues to cook foods
even after it's been removed from the oven. A rule of thumb is to reduce the
oven temperature about 25 F (14C).
Check the manufacturer's recommended care and use
instructions before using any glass, ceramic and glass-ceramic bakeware. These
items are usually cleaned with hot sudsy water and soaked if food has been
burned on the item. Avoid knives, sharp kitchen tools, scouring pads and
abrasive cleaners so that surfaces remain in their original smooth finish. This
is especially important for ovenware with nonstick interiors. Nylon and plastic
scrubbers are acceptable for stubborn sticking problems.
NONSTICK FINISHES
Efforts to ease the homemaker's kitchen tasks have received a solid boost in recent years with the development of nonstick finishes on cookware interiors and exteriors. The advantages of nonstick surfaces are obvious. They clean easily and quickly. Grease and food can be washed away with a sudsy sponge. A dieter can fry food using less fat, and the food won't stick to the utensil.
Fry pans were the first utensils to be given nonstick finishes. Now almost every cookware and bakeware item is available with a nonstick surface. There are griddles, saucepans, casseroles, muffin pans, cookie sheets, Dutch ovens, egg poachers, cake pans, deep fryers, waffle bakers, and many others.
Many accessories have been introduced. There are nonstick finished kitchen tools, such as spoons, spatulas, and egg beaters, for use with nonstick cookware. There are items that work better or are easier to clean when coated with a nonstick finish, such as rolling pins and ice cream scoops.
Basically, nonstick finished utensils should be used and cared for in the same manner as metal cookware and bakeware. Before first use, the utensil should be washed in hot sudsy water, using a soft sponge or dishcloth. It should then be rinsed and dried. Do not use abrasive scouring pads or powders.
Many manufacturers recommend that nonstick fry pans, Dutch ovens, and bakeware be seasoned with cooking oil before they are used for the first time. Cooking oil should be wiped on the nonstick surface with a paper towel - and the utensil is seasoned.
An exception is the tubed angel food cake pan. It should not be oiled or greased if it is used for angle food or sponge cakes, because the batter must cling to the sides of the pan during baking time.
For baking cakes that contain fruit or a great amount of sugar, greasing usually is necessary to insure complete release of baked goods from the surface of the utensil.
In most cases, simply use nonstick bakeware just like any other bakeware, following recipe instructions for greasing and flouring baking pans. Most homemakers find that oils, fats and butter may be desirable in frying, not to prevent sticking, but to contribute to the flavor of foods and also to aid in even browning.
Eggs have a tendency to stick slightly; however, cooking them with a small amount of fat aids in the release from the pan.
High heats should be avoided in most top-of-range cooking and particularly with nonstick utensils. "Low" to "medium" heat settings will give excellent cooking results without either warping the utensil or staining the nonstick finish, as well as making cleaning easier.
Use detergents in washing a nonstick pan after every use, so that grease or residual food will not cling to the interior. Pans may need to be re-seasoned after each washing in an automatic dishwasher. Be sure to place coated pans carefully in the dishwasher so that they will not be scratched.
To Remove Stains
Simmer any of the following solutions 15-20 minutes in the stained pan:
- 1/4/Dip-It* Coffee Pot Cleaner in 1 qt
water OR;
- 3 Tbsp. Snowy Bleach** (oxygen bleach
for delicate fabrics) and 1 tsp. Liquid dish detergent in cup water OR;
- 3 Tbsp. Automatic-dishwasher detergent in 1 cup water.
Rinse, dry and again
"condition" with shortening or cooking oil.
Non-stick finishes may be scratched by sharp or
rough-edged kitchen tools. The scratches effect only the appearance,
not nonstick properties of the finish. Scratches do not widen, nor will the
finish peel, chip or blister if it has been properly applied.
While smooth-edged metal tools can be used on hard-coat
nonstick finishes, it is suggested that you follow manufacturer's instructions.
Some of the familiar names for nonstick finishes are
"Teflon", "Ultralon", "SilverStone",
"Xylan", fluorocarbon, and silicone. In addition, there are nonstick
cooking sprays that you can apply to uncoated cookware before each use. They
are vegetable, oil-based products packaged in cans or bottles which are
available at grocery stores. These vegetable coatings are not a permanent
finish.
*Economics Lab., Inc., St. Paul, MN 55102
**Gold Seal Co., Bismark, ND 58501
