The golden rule of jam-making is to transform your fruit into jam as quickly as possible. Why? We want to capture the fresh fruit flavor rather than have an over-extracted, cooked fruit flavor.
Five features make the copper jam pan special:
Depth-to-surface area ratio: Having a wide pan base and shallow sides allows for all of the fruit to be exposed to the cooking surface, enabling a faster cook-time.
Slanted sides: This feature allows water to condense, steam and evaporate quickly without trickling back into the jam.
Smoothness of copper: Run a rubber spatula across the bottom of a stainless-steel pot and you’ll feel a little bit of a drag. With copper, it’s completely smooth, so you can really feel the textural changes and get in tune with the consistency of your jam.
Heat conductor: Copper is an excellent heat conductor which means you’ll get a rapid, even boil and your fruit will cook down quickly and evenly.
Heat Retention: When you turn off the flame, the jam will immediately stop boiling, whereas stainless steel or dutch ovens will retain a good bit of heat, taking time to cool down. This gives you more control over the process (when it's done, it's done!) and allows you to maintain the integrity of the fruit for that perfect texture.
But is Copper Safe to Cook In?
Copper (as well as iron and aluminum) will react with acidic and alkaline foods, so you have to be careful what you cook in it. Since nearly all fruits are acidic (even ones that we consider very sweet), there is cause for concern when using unlined copper for cooking fruit confections like jams, marmalades and chutneys. Putting fruit or fruit juice directly in the pan on its own will cause the fruit to react with the copper and can leach copper into your foods. The key to using a copper pan safely for confections is to mix the fruit and sugar before putting it in the pan. The sugar neutralizes the acidity and prevents an acidic reaction. As a result, you should also never prepare or macerate your fruit in unlined copper. Use glass or ceramic instead. For jams, marmalades and chutneys, follow traditional recipes (ie: with plenty of sugar) like those sourced on our website, from our workshops, or from the Blue Chair Jam Cookbook (available in the shop) which references the use and virtues of copper jam pans! Copper pans are not suitable however for sugar-free or low-sugar jams.