The pink lustre of a copper casserole dish adds a touch of elegance to any roast dinner but copper cookware is more than just a pretty face in a chef's batterie de cuisine.
'Copper has excellent heat conduction [10 times that of stainless steel or glass], which allows for the most even results in cooking,' says David Lai, a classically trained chef who is buying copper cookware for his as yet unnamed restaurant, which will open on Gough Street.'Its reaction time to heat change is unparalleled, which gives me greater flexibility and control. When I roast meat, or brown bones for a stock, I look for even caramelisation without any burned bits.'
For stove-top cooking, copper saucepans give a comfortable lead time for stirring and adding liquid (for a risotto) or turning down the heat before burning sauces or caramelised sugar.
Seasoned pastry chefs prefer whipping egg white in unlined copper bowls. Copper ions react with the protein and the peaks stay smooth and firm.
'Traditionally, the insides of copper pots and pans are hand-painted with tin - which corrodes with use and needs refurbishing once in a while. It's hard to find re-tinning services in Hong Kong. Most of the higher-end stuff is plated with stainless steel, which takes higher temperatures and lasts longer,' Lai says.
'Quality copper cookware - usually made with 90 per cent copper to 10 per cent steel - can be expensive. A small pot might cost more than HK$2,000 retail. You can find cheaper versions made with less copper but you lose the benefits; those would be used purely for aesthetics. If you can afford it, good copper cookware is worth it. With proper maintenance, it can last a lifetime.'
Copper cookware has a reputation for being high maintenance but daily care is no different than for any other cooking tool - clean, dry and store properly. Copper has a tendency to oxidize, which turns the outer layer a dull grey. While that does not affect the taste of the food, the sight of a warm, polished surface adds to the experience, from cooking to serving. Traditional ways to clean copper pans use what is available in the kitchen: rubbing the pot with a mixture of vinegar and salt; some cooks like to add egg white or a handful of flour for a thicker consistency. For heavily oxidized equipment, most experts recommend using a commercial cleaning agent. There are also commercial coatings that can be sprayed on after cleaning to maintain the shine.