creme de la creme (n.)

early 14c., creyme, "the rich and buttery part of milk," from Old French cresme, craime, creme "chrism, holy oil" (13c., Modern French crème). This word is a blend of Late Latin chrisma "ointment" (from Greek khrisma "unguent;" from PIE root *ghrei- "to rub") and Late Latin cramum "cream," which is of uncertain origin, perhaps from Gaulish. The French word replaced Old English ream; it was re-borrowed 19c. as creme.

From early 15c. as "dish or confection made from or resembling cream." The figurative sense of "most excellent element or part" is from 1580s. It is attested from 1660s as "any part that separates from the rest and rises to the surface" and also in its application to substances resembling cream. Cream-cheese is from 1580s. Cream-soda is attested by from 1854. Cream-colored (also cream-coloured) "having the pale, yellowish-white color of cream," is from 1707.