Olive Wagyu

Olive Wagyu, sold within Kagawa Prefecture's Sanuki Wagyu family, is finished on toasted, dried olive pulp, the lees left over after pressing olives for oil on Shodoshima, the island that produces most of Japan's olive oil. A Shodoshima cattle farmer named Masaki Ishii began experimenting with the idea around 2006, inspired by traditional persimmon-drying, and it took him roughly three years to perfect a way of toasting the pulp that cattle would eat. Olive Wagyu reached the United States around 2018.

Producers and importers describe Olive Wagyu as a small-production line and publish changing herd or harvest counts. Those figures should be treated as dated producer reports rather than a measured claim that it is the world's rarest beef. Certification is overseen by the Sanuki Wagyu and Olive Wagyu Promotion Association, which awards Gold and Silver labels under its program.

Producers report that olive feeding changes the beef's fatty-acid profile, including oleic acid. Oleic acid can be relevant to fat softness, but it is not a measure of umami, which is associated with taste compounds such as glutamate and nucleotides. Descriptions such as sweeter or more savory are sensory and producer claims rather than consequences proved by an oleic-acid percentage.

Look for the Sanuki Olive Wagyu name, Kagawa origin, and any applicable Gold or Silver Label. Those are checkable product claims; price or a rarity statement is not proof.