Écorce vs. peau vs. pelure
When discussing the exterior layers of items in French, be it fruit or otherwise, the terms 'écorce', 'peau', and 'pelure' are often utilized, each with its own particular context of use. While all of them can be used to refer to some form of peel or skin, they are used in different ways.
Écorce
'Écorce' refers to the thick, protective outer layer of trees or certain fruits like oranges. It is equivalent to 'bark' in English when describing trees.
L'écorce du chêne est rugueuse.
(The oak's bark is rough.)
On utilise l'écorce d'orange en pâtisserie.
(Orange peel is used in pastry making.)
Peau
The word 'peau' refers to the thin covering of an animal's body, and is also used to refer to human skin or a thin layer covering something, such as the skin of a drum or a thin layer on milk. In relation to fruit, it suggests a more delicate and edible skin, such as that of an apple.
La peau de l'éléphant est très épaisse.
(An elephant's skin is very thick.)
Il ne faut pas jeter la peau des pommes; elle contient des vitamines.
(You should not throw away the apple peel; it contains vitamins.)
Après avoir bouilli le lait, retirez la peau qui se forme sur le dessus.
(After boiling milk, remove the skin that forms on top.)
Pelure
'Pelure' specifically refers to the thin outer layer or peel of a fruit or vegetable that is usually removed before eating. It's similar to saying 'peel' something in English.
Les pelures de pomme de terre peuvent être frites pour en faire des chips croustillantes.
(Potato skins can be fried to make crispy chips.)
Ne jetez pas les pelures de carotte; elles sont comestibles et nutritives.
(Do not throw away carrot peels; they are edible and nutritious.)
Summary
In summary, while 'écorce', 'peau', and 'pelure' can be translated in English as peels or skins, 'écorce' is mostly reserved for tree bark and thicker rinds such as those of citrus fruits, 'peau' ranges from animal skins to other forms of thin coverings, including human skin and certain fruit skins, and 'pelure' refers primarily to the peels of fruits and vegetables that are often discarded during food preparation. Understanding these differences allows for accurate expression in both French culinary and botanical language.