Updated March 2026.
Sour mash is a process, not a TTB class of whiskey. Distillers add leftover stillage — backset — to the next mash so fermentation stays consistent. does not list “sour mash whiskey” as a type. Jack Daniel’s Old No. 7 prints 40%. Jim Beam White prints Proof 80. Most bourbon is sour-mashed and is still labeled bourbon. A 1.5-ounce pour at 40% is one NIAAA drink.
Related: sour mash whiskey, bourbon vs sour mash, straight bourbon.
Process vs class
| Language | 1.5 oz drinks |
|---|---|
| Sour mash | — |
| Jack Daniel’s Old No. 7 | 1.00 |
| Jim Beam White | 1.00 |
| Sweet mash | — |
A 750 mL 40% bottle is about 17 drinks. Four pours are four drinks. Pour math: whiskey drinks.
Sources
- 27 CFR 5.143 — no sour-mash type. Jack Daniel’s Old No. 7 40% Brown-Forman US sheet / jackdaniels.com prior. Beam White Proof 80 prior official.
- NIAAA December 2025.