Nabisco’s Oreo cookies became officially kosher in December 1997 , when they received Orthodox Union (OU) kosher certification after a multi‑year reformulation and production change process.

Quick Scoop

  • For decades, classic Oreos were not kosher because the recipe included lard (rendered pork fat), which is forbidden under Jewish dietary law.
  • In the early–mid 1990s, Nabisco removed lard from the Oreo formula, partly for broader health and marketing reasons, which opened the door to kosher certification.
  • After that, the company spent more than three years “koshering” its production lines and ovens to meet Orthodox standards across its facilities.
  • The Orthodox Union then certified Oreos as kosher in December 1997 , and OU symbols began appearing on packages soon after.
  • Today, most standard Oreo varieties remain under OU supervision, though specialty or limited‑edition products can have different kosher status and should be checked individually on the package or current OU lists.

In short: Nabisco “went kosher” with Oreo at the end of 1997, after removing lard and completing a multi‑year koshering of its equipment and supply chain.

TL;DR: Nabisco’s Oreo became kosher with OU certification in December 1997, following the removal of lard and a several‑year process to kosher the production lines.

Information gathered from public forums or data available on the internet and portrayed here.