The advent of products such as Kansas Clean has revealed a shocking truth. Distilled spirits that contain as little as five percent whiskey are allowed to call themselves whiskey. They can whiskey-this and whiskey-that all over the place, but is their product really whiskey? By law, yes. By common sense, no.
But law will trump common sense every time.
For you as a consumer, it shouldn't be necessary to memorize the Federal Standards of Identity for Distilled Spirits just to buy a good bottle of hooch, and it's not.
There is a simple, one-word solution, but the word to remember and look for is not 'whiskey,' it's 'straight.'
'Straight' is a modifier that applies primarily to American whiskey and not to most other types of distilled spirit. It means that certain specifications have been met, including aging in new, charred oak barrels for at least two years. It doesn't guarantee that the product will be good but it does guarantee that it will be what most people understand to be whiskey.
We're talking about American whiskey here, like bourbon or rye, not scotch, Canadian, or Irish. They have their own rules and peculiarities.
Straight whiskey (or straight bourbon, straight rye) is what most people mean when they just say whiskey. If asked to elaborate, they might call it 'real whiskey' or even 'pure whiskey,' but those terms are forbidden, at least on whiskey labels. That's okay as long as you know that the alternative is 'straight.'
If you want to blame someone for the semantic awkwardness of all this, the person you want is William Howard Taft, the 27th president, whose Taft Decision in 1909 allowed products that contain liquids other than whiskey to call themselves whiskey. It created different types of whiskey, the most whiskeyish of which is straight whiskey.
Unfortunately, there are a few straight whiskeys that don't have 'straight' on their label. Jack Daniel's doesn't and possibly can't, even though it meets all the key requirements. Even so, remembering to look for 'straight' is a good tip for anyone who wants guidance but doesn't want to get bogged down with details. 'Straight Bourbon,' 'Straight Rye,' and 'Straight Whiskey' are the terms you want to see. 'Straight Wheat' too, but there's not a lot of that around.
If you don't see 'straight' on the label, either find out why, or simply move on.