https://hopscalculator.chrisspeck.com/
Hops are one of the four key ingredients in beer making.
When sharing or creating recipes brewers will select a style and aim for a target IBU (International Bitterness Units). Hops will be specified in terms of timing, weight and AA (Alpha Acid %) to achieve the target IBU.
Missing the IBUs by being under or over is enough to miss the style, which means you are not making the beer you intend to be making (though it may still be quite good).
Unfortunately, the hops which home-brewers have access to tend to be whatever is left over after the commercial and craft breweries have had their pick.
This means the hops are usually old, and in any event usually has a different AA to that specified in the recipe.
This is a tool to help you adjust up (or down) your hopping addition so that you hit the target IBUs given whatever hops you have on hand.
The method is based on an article by Mark Garetz on MoreBeer.com:Hop Storage.
When you first go to the tool you will see the screen split into two halves.
Fill in the recipe and brewery details into the top half, then fill out the details for the first hop addition including target IBU, variety, and boil time.
The hops that you have are substitutions, because you don't have the exact fresh hops which the recipe calls for.
You can have one or more substitutions for each addition that the recipe calls for. Fill out the details including how much is available, rated AA, rating date, storage method and temperature and the tool will calculate:
- how much of that hop is needed to make up the IBU;
- what the estimated Alpha Acids are; and
- whether you've met the IBU target for this addition
Repeat adding more substitutions until you hit the target IBU for your first hop addition.
Then use the button to create a new hop addition, and repeat the process above.
If you have any feedback or questions about this tool you may open an Issue or PR (if you're on Github) or message me on Aussie Home Brewer. You will need to login to AHB before you can send messages.
Hop Storage, which outlines the process for predicting Alpha Acid decline by Mark Garetz.
Straight 2 The Pint: Dilution & Boil Off Calculator, which republishes the formula in Designing Great Beers by Ray Daniel.
Back To School Brewing: How to Calculate IBU's, formulas also based on Designing Great Beers.
Glenn's Hop Utilization Numbers.
Hop Cone Icon made by Freepik from Flaticon and converted using Favicon.io.
Licensed under the The GNU Affero General Public License, full text here.