What Are Your Pots & Pans Made of?

Cookware includes saucepans, milk pans, frying pans, woks, sauteuses etc which you use on various types of hobs. Also, casseroles and stockpots that you can use inside the oven. These cookware products are made of many different materials from the traditional enamel on steel to the cookware of today which is generally stainless steel. About 15 years ago a new type of hard anodised cookware arrived in the UK from America. This is growing more popular every year, you only have to watch a TV cookery programme to see it! We now also have new alloys like magnalite which come from the aerospace industry and claim to have improved durability and conductivity. And cast aluminium is back in favour particularly for grill pans. So with all these new ideas coming along, the future looks rosy for cooking.

But what of the past? Until the 19th Century we all boiled everything in large pots over an open fire. These pots were known as cauldrons, like the ones you see surrounded by witches in fairy tales. They were made of a mixture of copper and tin. But when “The Range” was introduced as the first type of kitchen stove we needed saucepans – and one of the first in the UK appeared in 1779 made by John Izen of Birmingham. These pans were similar to what we see today but were made of cast iron with a tin lining. By the 1840s cast iron pans with enamel coatings came onto the scene.

Set of saucepans from Meyer

The next big development in cookware was stainless steel which first appeared in 1913 but wasn’t used for cookware until the 1960s. Stainless steel was more durable than any previous material and soon became the most popular type of cookware. The only drawback of stainless steel is that it is relatively poor at conducting heat as compared to other materials:

Table of Conductivity

The materials listed above are those most commonly used for cookware. Each has its advantages and disadvantages for cooking pots and pans.

Stainless Steel

Stainless steel may be the new kid on the block when it comes to cookware, but it is by far the most desirable for customers. Its durability and simple functional design gives it an air of quality unmatched by any other type of cookware. It is hard-wearing and unless you treat it badly, it will keep its appearance well. Stainless steel is inert which means it will not react with either acid or alkaline foods. Available in a vast array of shapes and sizes it is almost impossible to find anyone who doesn’t have at least one stainless steel pan. How then can you tell good stainless steel from poor if there is so much around?

The one great drawback of stainless steel is that it is a very poor conductor of heat (see Table of Conductivity). This means that it takes a long time to heat up, wasting energy and time, and some parts of the base of the pan get hotter than others, known as “hotspots”, causing your food to burn.

One way around this is to buy pans that have a layer of high conductivity metal fixed to the base. Copper was often used for this but because it was very expensive the layer used was made thinner and thinner until it would not last as long as the pan. We now see aluminium widely used, also a good heat conductor and cheaper. Better quality pans now have thicker bases of 10mm or more which reach to the edge of the pans. This looks better and gives better results in dishwashers.

The latest manufacturing technique is called “laminating” where the whole pan body is made of three layers, stainless steel, aluminium then stainless steel again. This gives greater conductivity up the sides of the pan, cooking food all around, evenly, rather than from the base up.

Most saucepans are made with stainless steel handles which are much stronger and more hard-wearing than plastic. These handles will not get too hot with normal usage, unless the pan is on gas which has been turned right up. Pans with stainless steel handles can also be used in the oven.

Plain Steel

Steel pans, plain not stainless, are used by many professional cooks and enthusiastic amateurs. Because they are made using raw iron they can be heated to high temperatures and will, with long term use acquire a patina which makes them naturally non-stick. Many cooks prefer to use steel pans for paella and omelettes.

Hard Anodised Aluminium

This is the latest material to be used for making cookware. It has all the benefits of stainless steel, but is even more durable, without the drawbacks. It is an excellent heat conductor and heats up evenly so reducing the chance of hotspots.

Anodising is an electrolyte process which involves submerging the saucepan in a bath of acid and then putting a very high voltage through it. This changes the molecular structure of the surface of the metal making it many times harder. The dark grey colour of the surface of the pan gives it its distinctive look. It’s easy to clean and doesn’t show water marks.

Most hard anodised cookware in the UK is coated with non-stick it is ideal for “harsh” cooking techniques such as searing, browning, sautéing and deglazing. Look out for ranges that are also oven-proof so meals can be started on the hob and finished in the oven.

Finally, if your hard anodised pans do have a non-stick coating, metal utensils should not be used.

Cast Iron

This is one of the oldest materials for making pots and pans. It distributes and holds heat very well and is ideal for everything form frying pans to casseroles.

The way cast iron pans are made hasn’t changed much over hundreds of years. It is highly skilled and labour intensive. Every pan is made by pouring molten iron into pre-shaped moulds made from casting sand. Once this is cool, the moulds are broken open leaving the rough cast pan. The pan is finished off to end up clean, smooth and ready to be coated.

Traditionally the finish of the pan varies according to where it is made. For example, in the USA most cast iron cookware is now uncoated and the pan has to be seasoned before you use it. In Europe the most common coating is enamel, inside and out, which gives an easy-to clean and durable finish. And you can find these pans in a vast range of colours. The insides of some pans such as frying pans and griddles are sometimes coated using porous enamel which can have similar properties to non-stick pans.

But cast iron pans do have their drawbacks:

• They are very heavy because iron is a dense heavy metal.
• They can break if dropped onto a hard surface
• They are not recommended by most ceramic hob manufactures.

Benefits, however, are that cast iron is strong, durable, energy efficient and hygienic as it is impervious to acids and chemicals. It is even environmentally friendly because it is typically made up of 65% recycled iron and 35% pig iron. So, although fewer and fewer people were buying cast iron cookware during the early 1990s, this trend is turning around since the advent of TV cookery shows, new trendy colours becoming available and a return to traditional home cooking.

Aluminium

Sometimes known as brushed or uncoated aluminium, this product became popular in the 1920s due to its low cost. Aluminium is usually extracted from bauxite, one of the most abundant elements on earth which helps to keep the cost low. Being a soft metal it was easy to form, or spin into a wide variety of shapes.

These two factors as well as its excellent heat conductivity make aluminium popular with all types of cooks, especially caterers. As technology improved, new ways of using aluminium appeared so new pieces and intricate shapes can be made. But, the popularity of aluminium has dropped off dramatically in recent years due to bad publicity regarding health scares.

Enamel On Steel

Steel has been used to make cookware for a very long time due to its cheapness and good heating properties. Its main drawback has always been that it rusts very easily. This problem was overcome by coating the steel with a layer of enamel which protects it from the air and gives a smooth colourful finish. Because it comes in such a vast range of colours, enamel on steel remains a popular choice. The only problem is that it can chip because the enamel coating is brittle and can become damaged on the edges. This is normally overcome by adding a stainless steel band around all vulnerable edges. This type of cookware is ideally suited to non-stick coatings.

Copper

This was possibly the first metal used for making cookware because it was readily available and easy to form and the best of all conductors. But due to its great expense, its popularity has fallen over the years. It has another failing in that it develops a toxic coating when exposed to the air – verdigris. This was overcome by plating the inside of the pans with tin which was again a problem because it wore down quickly and couldn’t stand very high temperatures. The only solution to this problem was to coat the pan with real silver which made it even more expensive!

But copper is the king of conductivity in the kitchen. It is highly responsive, heating up and cooling down quickly. This makes it ideal for cooking foods that need rapid heat e.g. sealing and browning meat. Copperware lined with stainless steel is now considered by most professionals to be the finest cookware you can buy.

The heavier the copper pan the better. It should be at least 2mm thick. Lightweight pans might look pretty hanging on your wall but are not suitable for cooking with.

The disadvantages of copper cookware are

• It requires a lot of polishing to keep up appearances.
• It usually has brass, bronze or iron handles, all of which get very hot.
• It is expensive but if you look after it well it will last several lifetimes.

Glass

Glass saucepans are not a popular choice. The main problem is that glass pans hold heat and therefore continue cooking, and burning even when the heat is turned off. They are also heavy. But glass is widely used in oven-to-tableware. There is a great range of heat resistant glass products that can be used in the oven, fridge, freezer and dishwasher. Unlike metal cookware it can also be used in the microwave, it is scratch resistant and stylish enough to be put directly onto the table.

Glass Ceramic

Products such as casseroles and roasters made of glass ceramic are the most durable and versatile cookware available. They can withstand temperatures of up to 1000 degrees Celsius, a heat at which an aluminium saucepan would melt. Because of this high temperature resistance glass ceramic products can be used on top of the stove, be it a gas, electric or halogen hob, in an oven or in a microwave. Glass ceramic can also stand extremes of temperature, so it can be taken from a freezer and put straight to heat. And stylish enough to go straight to table!

Non-Stick Coatings

The invention of the non-stick coating is one of the great luck stories of modern science. Dr Roy Plunkett left his laboratory late one night not noticing that he had accidentally knocked over some test tubes that he had been working on during the day. Little could he have known that the waxy white material he found on his desk the next morning would eventually revolutionise the cookware industry, and help make his employers, DuPont, into the largest chemical company in the world.

So what was this new chemical that Dr Plunkett had discovered so fortuitously? Its full name was polytetrafluoroethylene but it is known simply as PTFE or “Teflon”. This chemical is one of a group called Fluoropolymers but its very low friction coefficient makes it uniquely “slippery”, and therefore ideal for use as a non-stick coating. The Guinness Book of Records has listed PTFE as the slipperiest substance on earth.

DuPont first patented their new coating in 1938 but it was not until the early 1960s that it first appeared on cookware. The first coatings did not fare as well as had been expected, due to their poor durability. What the makers had failed to realise was the amount of abuse cookware gets, particularly frying pans in day to day use. This led to the story that it was easier to make coatings for rocket engines than for frying pans.

Over the years new versions of non-stick have been developed. First came the multi-layer coatings like Silverstone which combined layers bonded together to improve durability. Then came coatings which had separate layers, the first layer bonded to the pan, the second acted to strengthen the bond and the third layer was the non-stick.

Later still, coatings were developed which combined metal filaments which greatly improved the coatings’ ability to bond to the substrate so improving its durability. At the same time as this was going on, other improvements were happening such as thicker coatings. Whereas early coatings could be as thin as 5 microns, newer finishes can now be up to 40 microns, again helping to improve durability. But nearly all non-stick coatings are vulnerable to scratching and overheating.

In recent years non-stick coating has been developed to suit the harder types of metal in our choice of pots and pans. That is, stainless steel, hard anodised and cast iron. Many companies now produce non-stick coatings in an increasing variety to suit the particular pan or baking tray it is applied to. New developments mean that colours can be added and you can now choose colour co-ordinated ranges that suit you. Looking back it is hard to believe that this all started with a little accident back in 1938.