Nearly 70 years after Jim Beam, Jasper Newton "Jack" Daniel was taken in by distiller Dan Call, where he learned whiskey-making. After World War II, the distillery flourished.
Both whiskeys use limestone-filtered water during production, which adds a slightly sweet flavor, but while Jim Beam uses column stills, Jack Daniel's uses copper stills.
Moreover, Jack Daniel's differs due to a process called "Lincoln Country Process," in which the whiskey is filtered through charcoal for three to five days, mellowing it out.
Jack Daniel's mash is only slightly different, consisting of 80% corn, 8% rye, and 12% barley, and the higher corn content technically makes it a bourbon.
Jack Daniel's whiskey is aged in charred American White Oak barrels, but instead of aging for a specific time, it's bottled when it reaches the Master Taster's expected quality.
In general, Jim Beam tastes bolder and spicier while Jack Daniel's is mellow and sweet, but both whiskeys display a range of flavors across their many offerings.
While both brands have many offerings, Jim Both is known for its "White Label" Kentucky Straight Bourbon, while Jack Daniel's specialty is its "Black Label" Old No. 7.