Calculation
A simplified equation from Ray Daniel’s Book Designing Great Beers for IBUs is:
- IBUs = U% * (ALPHA% * W_OZ * 0.7489) / (V_Gal)
Where:
- U% is the hop utilization in percent
- ALPHA% is the percent alpha for the hop variety
- W_OZ is the hop weight in ounces
- V_GAL is the volume of hops in gallons.
Note that the hop utilization U% varies by boil time, wort gravity, and a number of other factors. Also, this gives the IBUs for a single hop addition. If you have multiple hop additions, you need to add up the IBUs from each.
Example:
| Boil Size | 13.82 Gal |
|---|---|
| Pre Boil OG | 1.058 |
| OG | 1.062 |
| Amount | 2 oz |
| Alpha | 8.2% |
| Time | 60 min |
IBUs = U% * (ALPHA% * W_OZ * 0.7489) / (V_Gal)
= U% (0.082 x 2 x0.7489 ) / 13.8 gal
=
References
| Reference | URL |
|---|---|
| Calculating Hop Bitterness: How much Hops to Use? | https://beersmith.com/blog/2008/04/20/calculating-hop-bitterness-how-much-hops-to-use/#:~:text=A%20simplified%20equation%20from%20Ray,*%200.7489)%20%2F%20(V_Gal) |
| BITTERNESS (IBU) CALCULATOR | https://www.hopsteiner.com/ibu-calculator/ |
| Bitterness Calculator | http://www.realbeer.com/hops/bcalc_js.html |