We joined other burger lovers and tried Arby’s new Wagyu Steakhouse Burger

Arby’s and Wagyu. Bet you never expected to see those two words together!

The eatery best known for roast beef sandwiches for the past 60 years has thrown down the gauntlet in the fast-food world, introducing the Wagyu Steakhouse Burger — featuring the premium beef prized for tenderness — at its more than 3,500 locations.

We headed to Sunnyvale, home to one of the only Arby’s remaining in the greater Bay Area (there are also locations in Fairfield and Tracy) to give it a try. Two versions are available, the Deluxe ($7.49), with American cheese, tomato, lettuce, red onion, pickles and special burger sauce, and the Bacon Ranch ($7.99).

Demand was high on Day One. By 4 p.m., the staff served about 100 Steakhouse Burgers, double what they expected to sell.

What Arby’s promised:

The patty is a blend of 48% ground beef and 52% American Wagyu, which is a cross between Japanese Wagyu and top American cattle breeds. Arby’s says it’s the largest single patty offered in the fast-food or quick-service segment, with a weight of 6.4 ounces before cooking. That makes it 50% larger than a McDonald’s Quarter Pounder.

“Instead of focusing on making billions of mediocre burgers, we’re taking a stance on high-quality meat that deserves to be cooked properly,” Patrick Schwing, chief marketing officer of Arby’s, said in a statement. “We’ve spent over two years of dedicated research and development to deliver a premium burger that redefines what’s possible from a drive-thru.”

What customers thought:

Local resident Leslie Fox said “curiosity” prompted him and Keith Rollin to head over to the eatery at El Camino and Bernardo for the new burger. They ordered the Bacon Ranch.

“I like it,” Rollin said. “I really do. I’d have it again.”

Fox echoed that sentiment. “I think it’s really good, actually.” He had tried the Wagyu cheeseburger at Pacific Catch and thought this one compared favorably — and it’s about half the price.

What we thought:

No flimsy fast-food patty here. Arby’s came through on the promise to deliver a hot, hefty burger that’s got a good sear outside and — surprise! — a hint of pink inside.

But the methods used to achieve that appealing degree of doneness — first the cheffy “sous vide” treatment and then a quick dip in the fryer — result in a burger that’s decent but lacking the “craveability” and flavor of a burger off the grill or flat top.

How can Arby’s amp up that factor? Assuming the cooking methods don’t change, the restaurant chain could consider adjusting the other components — maybe grilling the onions or reformulating the sauce.

The verdict:

Give the Wagyu Steakhouse a whirl, especially if you are someone who likes a burger cooked to medium and not well done. (Want well done? They can accommodate you.) Tell us what you think.