Unless you consider it heresy to put anything but bourbon into that julep come Derby Day on Saturday, consider Michter’s Original Sour Mash Whiskey. It has a honeyed welcome, like bourbon, with notes of tropical fruit and a lingering smoothness hinting of spice on the finish. It’s as lovely straight up as it is with mint, sugar and water. It was once the most popular spirit made by Michter’s, a Kentucky distillery that traces its lineage to 1753: The whiskey, 86 proof (43 percent alcohol), is $46 for 750 milliliters at Park Avenue Liquor Shop, 292 Madison Avenue (41st Street), (212) 685-2442, parkavenueliquor.com, and $41.99 at drinkupny.com.