Aluminum has good thermal conductivity, and provides even heat if very thick. It is highly reactive with both acidic and alkaline foods, which can effects flavor and color. It is soft and prone to scratching, is light and inexpensive. Most commercial kitchens use very thick aluminum pans. Aluminum is considered unsafe for direct cooking.
The best quality stainless steel, 18/10 or SAE 304, is an alloy containing 18% chrome, 10% nickel and 72% iron.
Aluminum with an interior and exterior Lining of stainless steel
This design is often called "fully clad." or all clad. It is a moderate compromise solution and results in a medium quality pan. It does not have any particular advantages for heating large volumes of thin liquids in stock pots.
Thick Copper with an Interior Lining of Stainless Steel
These are the very expensive heavy European pans. The Copper tarnishes quickly. This does not affect performance.
Most pans are 2.3 mm of copper bonded to .2 mm of stainless steel. Cheaper versions have less copper. Falk holds a patent on this bimetal process.
Falk Culinair developed the process by which stainless steel and copper are bonded together. All cookware employing this design is made from the exact same materials, regardless of price.
Copper + Aluminum + Steel
This is the optimum solution if the copper is thick. Many tri-ply pans use 0.5 mm copper which is essentially a veneer. Our pans use 1.5mm copper and are 3.5mm thick.
• Copper is very conductive.
• Aluminum is almost as good
• Steel is not very conductive.
• Heat capacity is high for steel
• Ideal thickness is more than 3mm.