People tend to shy away from using “raw”, i.e. unlined, copper pans in the kitchen. Part of the reason is the “fear” of copper toxins leaching into the food cooked in them. Yes, copper is poisonous (well really anything is if you ingest enough of it). The trick with raw copper pans is not to use acidic food in them, i.e. fruit, tomatoes etc. So how to make jam, because a lot of fruit is acidic? For example strawberries have a pH of 3-4, making them just as acidic as oranges, stone fruit, and even pineapple. Cooking a mushroom cream sauce with butter, milk, flour and mushrooms in it would have much less effect because the pH of all these items is between 6-7 (water is 7). The reason unlined copper bowls are so safe for whisking egg whites is that they have a pH as low as 7.6 at the time they are laid, and can increase to about 9.4 with age.
A copper pan for confectionary
Well it turns out that the sugar used in making jam nullifies the effects of the acidity of the fruit – glucose and fructose inhibit oxidation. The trick is to put the fruit in the pan only after is has been combined with the sugar. Never prepare or macerate fruit in unlined copper. How much copper leaches into jam? Research done by Kevin West in his preserving book, “Saving the Season“, suggests one tablespoon of apricot jam made in a copper pot contains 2% of the daily requirement of copper.
Making strawberry jam
I have one unlined copper pan, a confectionary pan I bought years ago for a great price. I don’t use it that often, but for making jam, it shines. An ideal copper pan for making jam is of course a dedicated jam pan… the shallowness and slightly flared sides are perfect, allowing moisture to evaporate quickly. A small unlined pot is also handy for making hard candy and melting sugar is another great piece to have if you are into this kind of cooking. One such example is this small sugar pan from Mauviel.
The finished strawberry jam
NB: Occasionally you see sets of unlined pans for sale on Etsy. They are nearly always cheaper than lined pans.
despite the snow 