secret ingredient; subtle seasoning
A small amount of an ingredient added to a dish to subtly enhance the overall flavor without being directly noticeable. Often used in cooking contexts, but can also be used figuratively for a hidden element that improves something.
The secret ingredient in this curry is chocolate.
Professional chefs sometimes use miso as a subtle seasoning.
Standard kanji spelling.
Mixed kana-kanji spelling sometimes seen in casual writing.
Compound of 隠し (kakushi, 'hiding') + 味 (aji, 'flavor'). The exact origin is uncertain, but it likely emerged in culinary contexts to describe a technique of adding a small amount of an ingredient to enhance flavor without being overtly detectable.