For beef lovers, nothing can compare with a melt-in-the-mouth slice so tender and sweet that its provenance is as instantly recognisable as that of a wine from a leading vineyard.

Kobe, Matsusaka and Maezawa - the leading names in Japanese beef - have gained a following among Thai gourmets over the years and can be found in a selection of Bangkok's best restaurants.

But knowing the names is not enough to ensure quality, says Yumi Nohara, a member of a Japanese beef selling family from Sado Island.

"Each type of beef carries a grade. A5 is the best and A3 is reasonably good. We also have B5 all the way down to B1," explains the 28-year-old owner of Sadoya (literally "shop from Sado Island"), a new Japanese beef restaurant that only serves cuts in the A5 category.

"And you never know the grade of beef - be it Kobe, Matsusaka or Maesawa - that a restaurant is serving you. That is unless you have a trained eye like my father."

Growing up in Japan, Yumi was taught how to recognise beef by taste by her dad, a respected chef and a butcher.

Papa Nobutoshi searches out the best beef from Japan and only buys from trusted connections through bidders at the country's calves auctions. A5 beef is rare because at each auction, only one calf out of between 30,000 and 50,000 qualifies for the top-quality standard.

"The A5 standards include the percentage of marbling of the calf as well as her blood origins. We need to know whether three generations before that calf are pure-blooded Tajima calves," says Yumi.

"Also, both bidders and buyers must have the right certificates to buy and sell the calves, and the buyers need to secure good connections to the sellers on top of that."

"So, withA5 beef, you are talking about rarity and exclusivity. That's what the connoisseur wants."

Whether Kobe, Matsusaka or Maezawa beef, the calves come from Wagyu or Tajima cattle. The marbling of the fat is the result of the unusual DNA these calves pass down from one generation to the next, says Yumi, and has nothing to do with the myth that Japanese cow farmers massage the beer-drinking cows to create them.

"There's no way that the calves will get marbled texture through massaging," says Yumi.

"In fact, the marbling nature is a quirk. But as it suits the taste buds of beef lovers, we've perpetuated the pure breed of this special DNA throughout generations."

Tajima is a dominant black cattle strain raised throughout Japan, and each town tries to promote its calves through national auctions.

Kobe, Matsusaka and Maezawa beef-is renowned for its quality, which is largely due to each area's unique water and the types of grass and grains the calves eat.

Kobe beef can come from either female or castrated calves while Matsusaka and Maezawa must be from female calves only.

"Female calves are more delicious and only those who fall into at least A3 categories can truly be called Kobe, Matsusaka or Maezawa."

At Sadoya, only A5 Japanese and local beef are served. Yumi says the rarity of the A5 calves makes it impossible for her restaurant to only serve A5 cuts.

"It would be impossible for us to obtain prime A5 beef all the time. Restaurants in Japan are literally killing each other for it because they know that an A5 pure breed can be sold at any price. However, each Japanese town has its own specialities and we choose only their A5 calves for our customers."

Since the beef is so good, Japanese connoisseurs order it lightly grilled and just sprinkled with salt. It literally melts in the mouth and never gets caught in the teeth.

"You must not put pepper on this beef or it will ruin the taste," explains Yumi.

"The meat is so light because the fat can actually melt in the hand at normal body temperature. This means you do not have to worry that eating lots of A5 Japanese beef will clog your arteries. It's very easy to digest as well."

As for the widespread myth that Japanese calves drink beer to create the marbling texture, Yumi explains that the beer culture can about to comply with the Japanese government's chemical-free policy.

"Usually, the calves are fed medicines to help them digest the grass and grains," she says.

"But six weeks before going to the abattoir, farmers cannot feed them the usual medicines, so they get beer to help them relax and relieve some gas in their stomach.

"But this again has nothing to do with the marbling texture. That is the DNA that only the special ones can inherit."

Sadoya's A5 Japanese beef costs between Bt1,200 to Bt1,800 for 100gm. Set menus (Bt2,500-Bt5,000) are also available as is a set of choice with A5 beef, pork and seafood served with rice and soup.

Set lunches range from Bt220 to Bt250, including Japanese style hamburger, yakiniku, beef stew and beef curry. Yumi also makes a delicious spicy udon (Bt280).

And anyone in search of a new gourmet experience should ask whether the restaurant is serving kurobuta, or black pork, a special breed of pig from Kagashima Island in Japan's south.

The meat is firm and pink and tastes delicious grilled and eaten with Japanese BBQ, sauce, freshly ground green chilli and a spoonful of ground fresh garlic.

Sadoya is open daily from 11am-2.30pm and 5.30 to 10.30pm. The restaurant is in the Baan Silom project between Pramuan Road and Silom Soi 19. Call (02) 266 5191-2 for reservations.

The writer can be contacted at saleewong@gmail.com

Sirin P Wongpanit

The Nation