century the high-pectin, readily gelled sour
orange had begun to replace the quince.
Marmalade made with sweet oranges doesn’t
gel as readily and lacks the characteristic
flavor, including a bitterness that helps
balance the sugar.
As is true for most fruits, the skin of citrus
fruits is more easily removed from the
underlying tissue by briefly immersing the
fruit in simmering water. Thick citrus rinds
require an immersion of several minutes. Heat
softens the cell-wall cement that attaches rind
to fruit, and may also encourage some
enzymes to begin to dissolve the cement.
Kinds of Citrus Fruits Trees in the genus
Citrus are wonderfully variable and prone to
form hybrids with each other, which makes it
a challenge for scientists to work out family
relationships. Currently it’s thought that the
common domesticated citrus fruits all derive
from just three parents: the citron Citrus