I think you’re confusing Tennessee Whiskey with sour mash. From wiki, sour mash is not a type or flavor of whiskey as is commonly thought. When a whiskey is sour mash, a portion of the old or "sour" mash is added to the new mash. (The old mash is also called "feed mash" because the old grains are used as an ingredient in animal feed.) The mash is the mixture of grain and hot water that the actual whiskey is made from. The sour mash process is done to improve the consistency and quality of the liquor so that every bottle tastes as close to the same as possible. The acid introduced by using the sour mash controls the growth of bacteria that could damage the whiskey. Sour mash is popular in bourbon whiskey and Tennessee whiskey.

Some of the brands that are sour mash and at the same time are bourbons are Evan Williams, George Dickel, Knob Creek, Maker’s Mark, Wild Turkey, and Woodford Reserve.

While Jack Daniels Single Barrel 94 proof is a pretty good whiskey, I think you’ll find a myriad of opinions on what the best "sipping whiskey" is. Personally, give me a double shot of Wild Turkey 101, Old Grandad 114, Ancient Ancient Age (not Ancient Age), Woodford Reserve, or 9 yr old Knob Creek and I’m good to go.

If you want a good utilitarian 8o proof whiskey, Jack Daniels can sure fit the bill.