What Tinseth does and doesn't model
Tinseth estimates isomerized alpha acids from boil time and wort gravity. It does not model whirlpool or hop-stand additions or dry hopping, which add aroma and some perceived bitterness. Different apps also disagree on pellet adjustments, so the +10% option is off by default.
Bitterness by style
Beer styles by the numbers (BJCP 2021 vital statistics)
| Style | OG | FG | IBU | Color (SRM) | ABV |
|---|---|---|---|---|---|
| 18A Blonde Ale | 1.038–1.054 | 1.008–1.013 | 15–28 | 3–6 | 3.8–5.5% |
| 18B American Pale Ale | 1.045–1.060 | 1.010–1.015 | 30–50 | 5–10 | 4.5–6.2% |
| 20A American Porter | 1.050–1.070 | 1.012–1.018 | 25–50 | 22–40 | 4.8–6.5% |
| 15B Irish Stout | 1.036–1.044 | 1.007–1.011 | 25–45 | 25–40 | 3.8–5.0% |
| 21A American IPA | 1.056–1.070 | 1.008–1.014 | 40–70 | 6–14 | 5.5–7.5% |
| 21C Hazy IPA | 1.060–1.085 | 1.010–1.015 | 25–60 | 3–7 | 6.0–9.0% |
Source: BJCP 2021 Beer Style Guidelines. Ranges are for judging; your recipe can sit anywhere inside them. Color swatches are an on-screen approximation.
Questions
How many IBUs is an IPA?
The BJCP 2021 range for American IPA is 40–70 IBU; hazy IPA is 25–60.
Why does a big beer get fewer IBUs from the same hops?
Higher boil gravity lowers utilization. Tinseth's bigness factor shrinks as gravity rises.