From The Straits Times    |

Aluminium, stainless steel or ceramic: Which should you use to help you cook better?


If you’re the sort who still views non-stick pans with suspicion, you can breathe easy now. This is because PFOA (perfluorooctanoic acid) – the substance that was used to make Teflon about a decade ago – is no longer used by most brands, notes Jakob Thorup Kristoffersen, Scanpan’s export manager for Asia-Pacific. Newer and better manufacturing technology means that brands can now provide non-stick and easier-to-clean surfaces in other ways – as in new materials like “pearl ceramic” for Corningware’s Retroflam.

PFOA was an emulsifier used for non-stick coatings. It is believed to be “likely carcinogenic” and causes health problems, Mr Kristoffersen explains. “Since 2008, Scanpan was the first to develop a PTFE (polytetrafluoroethylene, a non-stick coating) that does not contain any PFOA nor PFOS (perfluorooctane sulfonate anion) at any stage of the manufacturing process.”

“With cookware, one has to be aware of the adhesive that keeps the different layers together and of course the base materials used,” says Brigid Loh, business manager, Cookware for World Kitchen (South-east Asia). Low quality adhesive material can’t withstand high heat, and can break down and leach out, she adds.

World Kitchen, best known for their Corningware, Pyrex and Vision brands, recently launched a new metalware range, Corningware Retroflam. Corningware Retroflam cookware has five layers, cast into one entire piece from quality aluminium with no glued edges. The aluminium core is for thermal conductivity, the black titanium is a strong, non-toxic, non-porous, non-reactive, non-allergenic, biocompatible metal good enough for medical use. The final inner and outer layers are a sparkling pearl ceramic coating which seals the cookware interiors and exteriors, ensuring a non-toxic and non-stick hard surface, which is highly resistant to heat.

Ms Loh explains that the pearl ceramic coating is cured – not sprayed – on the interior and exterior of each cookware with nano technology, and is naturally inert and non-reactive to acidic and alkaline food, free from toxic chemicals such as PFOA, cadmium and lead.

“Even under extreme heat of up to 400 degrees Celsius,the ceramic coating will not emit chemical discharge,” she adds.

For trusted French brand Le Creuset, the cookware is made by melting iron at 1,000 degrees Celsius, and poured into individual sand moulds. “This casting method allows for a wide variety of shapes, styles and sizes,” explains Cheryl Yuen, Le Creuset Singapore’s commercial manager. When cooled completely, each sand mould is then broken around the cast iron piece. The pieces are then sanded and polished to remove round edges. A process of shot blasting is then carried out to prepare the cast iron surface for three layers of enamel coating.

The first coat helps prevent rusting, the second coat is colour enamel made up of powdered glass chips and pigment, for longevity of the product. The final coat is the graded colour exterior. “The vitreous enamel is fused to the cast iron during the manufacturing process. Fired at temperatures of 790-840 degrees Celsius (not just a simple drying process) allows the vitreous enamel to take on the strength of cast iron,” she explains.

Ms Yuen points out that Le Creuset regularly takes items from its production lines to be tested externally, for example, for lead and cadmium. Le Creuset wares come with a lifetime warranty, but they are susceptible to thermal shock damage which can’t be repaired. Ms Yuen says that even exposed raw cast iron is not harmful except that the enamel flakes can get into the food, so the cookware needs to be replaced.

Meanwhile, Danish brand Scanpan uses 100 per cent recycled aluminium, explains Mr Kristoffersen. How is a Scanpan cookware made? Products are squeeze-cast under 250 tonnes of pressure. In the following processes, 30,000-degree-hot titanium is bonded to the compressed aluminium and a non-stick coating is applied and tempered. “This unique casting technique ensures maximum durability and perfect heat distribution across the entire surface,” he explains.

Scanpan was the first manufacturer of cookware to introduce environmentally friendly, PFOA-free products to the market – and this prevents the transfer of harmful chemicals in cooking, he points out. “There is a time limit to using our cookware, but with proper care, they can last for many years,” he says, adding that Scanpan’s products come with a 10-year guarantee.

For WMF, the brand has also branched out into using ceramic for the first time. Its WMF NATURamic range, to be launched soon, has a steel core in order to be nickel-free (to protect against allergies). “Ceramic was chosen as it was the perfect time to rebrand our sister brand, Silit. By combining Silit’s technology in ceramic cookware and WMF’s design, we have the perfect premium cookware range – the WMF NATURamic Cookware line,” says Amanda Chang, marketing manager of WMF Singapore.

NATURamic is made by melting the natural ceramic material and fusing it with the steel core. It is baked twice at very high temperatures to get the perfect fusion. The end product is a high-grade ceramic cookware that is harder than steel, non-porous (requires less oil), and has super heat retention properties. “Cleaning is a breeze as food that’s stuck can be easily removed with a gentle sponge.”

Most top brands come with warranties, and some even up to 10 years or longer. Ms Loh highlights, though, that there’s actually a use-by deadline for most pots and pans. “Most of us don’t think about it – and will continue using the same cooking ware until something happens, like handles falling off or after we’ve burnt our pots and pans.” So, do pay attention to the materials used in the cookware, and be careful to heed the instructions for use and cleaning so that the cookware can last longer, she says.

World Kitchen’s Ms Loh highlights the pros and cons of other types of cookware in the market:


Aluminium is an efficient conductor of heat, it’s fire resistant and rust-free. However, aluminium is a soft metal and can be easily scratched and dented. It can also react with certain foods which is why it is usually sandwiched between other metals. Over time, a grey tone can form but this discolouration would not affect its usability in any way. Some aluminium cookware is also often treated through a process known as anodisation, where a layer of aluminium oxide is put on the surface to make it scratch-resistant and not reactive with foods. Aluminium cookware is often finished with a non-stick coating to guarantee food remains unburned.

Ceramic/ceramic-cured wares

Ceramic is derived primarily from silicon dioxide which is a major constituent of sand and minerals. It is an inert material that does not react to differences in pH in foods and they don’t leach any chemicals into food. They are the easiest option to clean, and have relatively durable surfaces as you can use scrubbing pads without scratching the surface. They have a non-stick cooking surface and hold in flavours in foods.

There are many ceramic-coated cookware in the market but it is important to look for those which are cured and not just spray-coated on aluminium/stainless steel. Cheaper-priced ceramic-coated wares are often just a thin layer of ceramic sprayed onto the aluminium/stainless steel and are not durable. Ceramic coating should be cured onto metal to ensure durability of coating.

Stainless steel

Efficient conductors of heat, stainless steel cookware is more stable than other cookware materials. Leaching of metals, including nickel, is less likely. An exception would be stainless steel pots and pans that have been damaged by harsh scouring with an abrasive material like steel wool. However, stainless steel cookware has very poor non-stick capabilities.

Enamelled cast iron

Enamelled cookware cooks evenly and with good flavour. When properly seasoned, the surface itself is great for cooking soups and stews. The only setback can be the sheer weight and high cost of cast iron cookware. Also, sometimes after prolonged use, the enamel lining wears or chips off and the iron in cookware material does leach.


Tricky to clean but stoneware gives amazing flavour to food and cooks very evenly. Along with amazing durability and scratch resistance, it also doesn’t stain and is easy to clean. High thermal resistance means that it can go straight from the refrigerator to the oven and back again without cracking. You won’t want to use soap, as the stone absorbs the flavour, but a properly cared-for stoneware piece can last a long time.


Professional cooks like copper for its superior heat conductivity but it is highly reactive with differences in pH in foods, so most copper pans are lined with either tin or steel. Tin wears out easily, and needs to be replaced every few years, which is why you should consider purchasing copper pots lined with stainless steel. Stainless steel-lined copper pots are more expensive but they last longer. Copper pots allows you to fully brown meats and proteins. But they need to be polished frequently when not in use, to prevent corrosion.

Copper cannot be washed in the dishwasher and must be hand-dried thoroughly after washing to prevent spotting. It cannot be scrubbed with steel wool, green gauzes, or abrasives, and never allow an empty copper pan to be heated up. Older copper cookware may have tin or nickel coatings and should not be used for cooking.

Glass cookware

Glass is inert, non-toxic, and safe and there is no danger of any chemical leaching. Glassware is heat-resistant, oven and microwave safe. Glass is non-porous, so the odours and flavours of foods cannot be absorbed into it. One of the most obvious benefits of glass is that you can see what you are doing as you make your dish. Glass also retains heat well and can be used for soups and stews. With proper care, they can last a long time. Glassware also offers versatile use, is safe for use on stovetops, ovens and the microwave.

Glass ceramic

Glass ceramic like the original Corningware Pyroceram has exceptional durability and promotes healthy cooking. Non-porous, it offers safe, versatile use on stovetops, ovens and the microwave. High thermal resistance means that it can go straight from the refrigerator to the oven and back again, being impervious to thermal shocks.