Updated March 2026.
Irish whiskey and bourbon are different legal classes, not two proofs of one spirit. Irish whiskey must be distilled and aged on the island of Ireland in wooden casks for at least three years. US bourbon is at least 51% corn, distilled under 160 proof, stored in new charred oak, and bottled at ≥40% ABV. Flagships (Jameson, Bushmills, Jim Beam White) are often 40% — a 1.5-ounce pour is then one NIAAA drink.
Triple distillation is common Irish practice, not a universal statute. Bourbon “straight” means ≥2 years, no added flavoring. Related: bourbon vs whiskey, Scotch vs Irish, Jameson.
What the statutes actually fix
| Irish whiskey | US bourbon | |
|---|---|---|
| Place | Ireland (GI) | United States |
| Grain | Malted cereals; pot still may include unmalted barley | ≥51% corn |
| Oak | ≥3 years, wooden casks | New charred oak (no minimum years unless “straight”) |
| Typical flagship ABV | 40% | 40–45% — read the neck |
| 1.5 oz at 40% | 1.00 drink | 1.00 drink |
A 750 mL 40% bottle is about 17 drinks. Four pours are four drinks. 90-proof bourbon is 1.13 drinks per 1.5 ounces. NIAAA binge pattern is a health line, not a target. No 2026 MSRP. Pour math: whiskey drinks.
Sources
- Irish whiskey technical file / GI: ≥3 years wooden casks on the island of Ireland.
- TTB 27 CFR 5.143 bourbon and straight bourbon.
- NIAAA December 2025. Triple distillation is practice, not a universal Irish legal requirement.
- (27 CFR 5.143)