Molecular Gastronomy

Red fruits should never be placed or cooked in unclean tin-plated copper pans

In preserves copper is found in the form of ions and possesses two positive electric charges that interact with the two negatively charged groups, causing the pectins to bond with one another. In other words, copper reinforces the pectin gels, hardening preserves, as experience shows.

In preserves copper is found in the form of ions and possesses two positive electric charges that interact with the two negatively charged groups, causing the pectins to bond with one another

that potato cells contain granules of starch, which swell when the cellular water is heated, forming a purée, and that because a potato is a thermally isolating material, its center is slow to cook. If the oil in the first round of frying is too hot, an excessively thick and rigid crust forms before the center is cooked, and the potato will not puff up