Two things Kentuckians know, right down to their marrow: They know their basketball and they know their bourbon.

Washington knows apples.

So here comes Costco out of Issaquah, Wash., that most mass of mass merchandisers, with its own brand of bourbon. “Kirkland Signature Premium Small Batch Bourbon.”

And my first thought is: Go back to Issaquah and stick to what you know! We wouldn’t come up to Seattle peddling Natural Falls of the Ohio pure bottled water. Or Genuine Bardstown Road mountain climbing gear. Or the Kentuckiana Digi-Tech Incubation Center.

You already have Amazon and Microsoft, Starbucks and Nordstrom — keep your hands off our bourbon.

The name Kirkland, by the way, refers to a nice-enough waterfront town in the Eastern Seattle area, right across Lake Washington. But it has no history of moonshine or stills, hooch-runners or revenooers. It’s not rural and romantic, it’s suburban and antiseptic. It’s probably about three months old.

And Kirkland is also the brand of all Costco private label merchandise. It would be like saying, “We’re out of bourbon right now, but try our Pappy Van Winkle frozen cheesecake.”

So am I just being grumpy and territorial? Is this stuff in fact drinkable?

“It tastes to me a lot like Jim Beam,” says Mike Veach, the official Bourbon Historian at the Filson Historical Society’s Bourbon Academy.

Is that possible? Can someone even figure out how to rip off the taste of the world’s No. 1-selling bourbon?

Not quite. And it’s not so treacherous. Certainly not illegal. And not in the least bit difficult. Just maybe — misleading.

“There are 10 licensed distillers in all of Kentucky,” says Jason Brauner, owner of Bourbons Bistro on Frankfort Avenue. “And these 10 distillers produce bourbon for about 300 labels — even including direct to the Japanese market.”

Most of the brands, familiar names, end up on liquor store shelves. And some are exclusive, distilled and marketed that way. For example, “I get my own private selection bourbon from Four Roses,” says Brauner, who offers about 130 different brands in his place. “It’s between 120 and 130 proof and you can’t get that product anywhere else on the market.”

And in some cases, it’s just a matter of slapping a label on something. Four Roses by any other name.

All legal and paid for. Not inexpensive. Just — misleading.

According to some of the people I talked to about this, many of our most familiar bourbon brands do not, in fact, have their own distilleries. Jefferson Reserve does not. Redemption buys somebody else’s “juice” and puts its label on it. The Pappy Van Winkle bottle says, “comes from the Van Winkel distillery,” but they in fact have no distillery. Their stuff, I’m told, is made at Buffalo Trace.

“When Woodford Reserve opened for business, they immediately started selling bourbon,” one person told me, “but they didn’t have any juice. So that initial Woodford Reserve was actually from honey barrels of Old Forester.”

And take a deep breath, Kentuckians: It turns out some Kentucky bourbon comes from Indiana. The Lawrenceburg Distillery, a former Seagram facility, produces bourbon under a variety of brand names, including Bulleit, Templeton, Filibuster, High West, James E. Pepper, Redemption and Smooth Ambler.

Think of it as Kroger private label grape jelly in the supermarket. Kroger isn’t in the business of making jelly. It was made exclusively for Kroger, probably by Smucker’s or Welch’s, with a Kroger label slapped on, to compete with Smucker’s and Welch’s.

“Costco no doubt bought its Kirkland Signature Premium from some brand name bulk distiller here in Kentucky,” says Filson’s Veach.

And therefore it’s probably wrong to dismiss the Costco bourbon as strictly bush league — the Washington State Podunk Association of Second-Rate Liquor Producers.

For one thing, as Jason Brauner says, “There’s no bad bourbon, just better bourbon.”

Veach calls the Kirkland product “not bad.” Bloggers on the Internet — and it’s astounding how many of them there are, for practically any given subject — have varying opinions.

“Overall, it’s not a bad option at a slightly lower price than Knob Creek, especially if you really like Knob Creek,” says therewillbebourbon.net.

“I can tell you without hesitation that it is thoroughly decent,” says sourmashed.com. “It’s not great, but it is not bad. Middle of the pack.”

“This was a bad bourbon,” disagreed Matthew Rowley of Rowley’s Whiskey Forge on matthew.rowley.blogspot.com. “Harsh, acrid, hard to get down.”

Also, bloggers being bloggers — i.e., obsessive — they all went after the same mystery we raised. Who distilled this?

“The label tells us that this bourbon is a seven-year-old, 51.5 percent bourbon,” says sourmashed.com. “Beam has a few seven-year-old bourbons, like Baker’s and Jim Beam Black, but the former is 53.5 percent and the latter is 45. Beam does not have any bourbon at 51.5 that I know of, but a few are close — Knob Creek and Old Grand Dad are both 50 percent.”

However, adds the blogger, “The bottle mentions Clear Springs Distillery and both Clermont and Frankfort, Ky. … According to a Certificate of Assumed Name filed with the state of Kentucky in March of 2011, the Clear Spring Distilling Company is in fact owned by Buffalo Trace.”

Mystery solved. Kirkland is from Buffalo Trace and tastes like Jim Beam — a little bit, anyway.