The use of various online calculators for brewing is common practice when generating a beer recipe. One that is often used is the IBU (International Bitterness Units) calculator. This calculator is used to report the IBU value of a beer based on several parameters. Even though calculators differ by parameter inputs as well as functionality, common information is original gravity (OG), pre/post boil volume, alpha acid content of hops used, and boil time for each specific hop addition. This study is a continuation of a previous study that compared the predicted IBU of malt extract-based worts ranging in OG from 1.001 to 1.095 to measured IBU using an organic extraction method. The current study finished out the wort OG analysis by testing additional OG values that were not previously tested. Furthermore, we examined if carbohydrates were the factor affecting these differences by generating worts using cane sugar as the sole source of carbohydrates in the wort. Results from this study determined that wort OG values less than 1.050 were not accurately predicted using an IBU calculator. Additionally, worts generated with cane sugar as the sole source of carbohydrate had significantly higher measured IBU values compared to predicted values compared to traditionally generated worts. These findings are important to brewers for three reasons. The first reason is that the OG range of many commonly produced beers are within the values 1.040 and 1.050. The second important finding is that IBU values predicted strictly on the basis of carbohydrate content may not be entirely accurate. The third reason is that brewers may need to adjust wort recipes for desired IBUs when the recipe calls for a large amount of straight carbohydrate additions.

Further characterization of IBU calculators using additional OG worts

254th National Meeting (2017)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.