new wine in an old bottle

• new wine in an old wineskin

From Matthew 9:17 of the King James Bible.[1]

new wine in an old bottle (plural new wine in old bottles)

1. (idiomatic) A significant change introduced to an entrenched system or method.
   • 2023 May 6, Marc Santora, Eric Schmitt, John Ismay, “Ukraine Claims It Shot Down Russia’s Most Sophisticated Missile for First Time”, in The New York Times‎, →ISSN:

     But Western analysts have remained skeptical, calling the missiles, modified versions of existing conventional munitions, “new wine in old bottles.”

2. (idiomatic) A new thing passed off as old.

See old wine in a new bottle.

• old wine in a new bottle