It was too early for lunch, but the tuna salad at Newcastle Produce looked great and sounded even better. It included cucumber, cilantro and a mustard of wasabi and lime, said the deli person. She showed us to the market's mustard shelf so we could get some to make the salad at home later, but the shelf was bare of that particular product.

The wasabi-and-lime mustard is one of 12 specialty mustards made by the specialty-food company Terrapin Ridge in Freeport, Ill. In sales, it's the hottest mustard going right now, says Kelly Monigold, the company's assistant general manager. Other varieties are brown sugar and pecan, sweet beet and horseradish, balsamic and herb, and hickory honey. Several of the mustards also are stocked by Taylors Market, but when I stopped by the Sacramento store the next day it also was out of the wasabi and lime.

I asked Monigold whether there's a shortage of the wasabi and lime. Nope, she said, though she speculated that the distributors for Newcastle Produce and Taylors Market may temporarily have run out.

Terrapin Ridge is a branch of the Furst-McNess Co., which has been making home products since 1908. About a decade ago two great-granddaughters of one of the founders began to create a line of gourmet specialty foods. Marketed under the Terrapin Ridge brand, they include dressings, squeezes and sauces as well as mustards. Their best-selling product is the "spicy chipotle squeeze," followed by the "natural hot wasabi," both garnishing sauces. The wasabi-and-lime mustard is their third most popular product. While several of their products can be found at local stores, the full lineup can be ordered online through the Terrapin Ridge Web site.