The calculator above is dedicated to the hops selections for your recipe. Begin by entering some information specific to the recipe you are creating. Provide the expected Final Gravity of your beer, the final Batch Size, and the wort’s Pre-boil Volume. The calculator will use this information to predict the pre-boil specific gravity of your beer for use in the bitterness calculations.
Enter the following information for each of your recipe’s hops additions:
- Select the hops you are using from the pull down menus on the left. Once selected, an average alpha acid value for that hops variety will be displayed in the %AA box for that ingredient.
- Enter the quantity, in ounces, you will be using for that particular hops addition.
- Select the Minutes Boiled for that particular hops addition.
- Next select the form of hops you are using from the pull down menu. This would be either Pellets or Whole Hop Flowers.
The calculator will then return the % Utilization and the Bitterness Units (BU) for that particular hop addition. At this point, you can change the Alpha Acid % for your particular variety if it differs from the values I have put in the database.
When you are done, the calculator will return the recipe’s Total IBUs (International Bitterness Units) in the box in the lower right corner. This number is a reflection of all of the hops addition’s contributions to bitterness based upon the gravity of the beer and the timing of each hop addition (each of which affect hop bitterness utilization). This number is also determined based upon your choice of Bitterness Formula. The formula choice is based somewhat upon personal preference. I prefer the Ray Daniels method of calculation where some people prefer the Tinseth method for full boil bitterness calculations. Feel free to use whatever method you prefer based upon your research.
The calculator will also return the BU:GU ratio for your current recipe. It reflects the ratio of bitterness to the gravity of the beer. This ratio was popularized by Ray Daniels in his book Designing Great Beers and is an excellent tool to use in order to maintain the same perceived bitterness level in a recipe despite its gravity.
Once the above steps are completed, you will know if your recipe’s hops additions allow it to fall within correct style guidelines for the type of beer you are producing. This will also allow you to compare bitterness levels with other beer styles and other recipes. If you like very “hoppy” beers, this value will be high. The reverse is true for beers that don’t have a strong “hoppy” character and are sweeter.
You can use this value to help you during recipe formulation as well. If you produce a particular beer recipe and it turns out to be incorrectly balanced, you can use this calculator to adjust bitterness values to produce the end result you are looking for. Also, if you are forced to substitute a hops variety in a recipe, you can see how it will affect the recipe’s final bitterness values and correct the quantities to obtain the same final bitterness level.