Code Name: Fantasia

Here's an interview with Jeff Fowler the chief developer of BeerTools.com about a new hop utilization feature for the GOLD interface.

L: So how long have you been with BeerTools?
J: Since the beginning in February, 1999.

L: A lot of changes to the tools have taken place since then, haven’t they?
J: Oh…(nodding) I would say so. BeerTools.com started with some very humble beginnings, and we still have much to do.

L: So to start off…what is hop utilization?
J: It’s one of the most complex parts of predicting beer characteristics. This is the degree to which the hops’ alpha acids are isomerized during the boil of the wort. Bitterness results from this process. Two main factors are taken into account when calculating this number. Boil time and specific gravity of the boil are used as variables in the equations. Other factors affect utilization but not as significantly as boil time and gravity.
BeerTools.com calculates the utilization using a 4th degree polynomial in combination with an exponential equation to provide a smooth curve over time. Thus any time or gravity can be entered to find a unique result on the graph. This method is better than using values found on a table because there are no gaps in the sequence of values.
There are several authors who have contributed their own tables and formulas to accomplish this same task, and interest has been expressed in seeing results based on the work of these various authors. While the formulas used at BeerTools.com are quite accurate, we decided to include results based on the work of these authors in the results page of the Recipe Calculator as well.

L: OK (chuckling) sounds pretty involved…how will this new feature affect results?
J: Fantasia will allow GOLD users to have the option of choosing which author they feel most comfortable with when calculating bitterness. Or, the previous method may be used as well.
Additionally, results from all the authors can be averaged to provide a composite result. This new feature will allow GOLD users to choose only those authors they would like to include in the results and average the result from the values produced.

L: So how did this new project get started?
J: It has really been an on-going project since the beginning of BeerTools.com, but this enhancement is a response to user feedback. User feedback is valuable to us, and we try to implement the ideas of our visitors when possible. This new project is really a continuation of our pursuit of accuracy. It will serve to give more credibility to the results currently produced by the calculator.

L: What is involved in building this?
J: In terms of writing code, each author’s calculations will be calculated separately and included in a table on the Recipe Results page. So the Results page will be redesigned and the code will have to be modified to include 6 more sets of hop calculations. These calculations will be performed for each addition of hops in the recipe. It’s a lot of math.
Then a method will be integrated to allow the user to choose which author she would like included in the calculations, and this information will be stored for when the user visits BeerTools.com again.

L: When do you project this new gold feature to come on line?
J: We have set a target date of May 12, 2001. We hope to meet it, but since we don’t like to release new features before we know they are functioning well, we may take a few days for thorough testing.

L: Are you brewing a batch anytime soon?
J: Yes, I have ingredients ready for an all-grain Belgian Tripel that I plan to brew within the week. This is my favorite type of beer.