This could be the Holy Grail of secret ingredients.

Rangpur limes look more like mandarins than the little green citrus fruit we know, but their flavor is like a smoky lime. This syrup pours easily—like honey—and doesn’t leave sugar crystals as it dissolves in iced or hot drinks, making it excellent for cocktails. It’s become a stealth ingredient in my mojitos and margaritas. A rangpur lime syrup gin and tonic, anyone?

Not into gin? Add it to yogurt. Drizzle over grilled fish. Drop a splash in a vinaigrette. I could keep going. This one is fun and easy.

From Robert Lambert, Santa Barbara’s resident citrus genius.

Very limited supply.