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Glenn Tinseth's IBU formula.


npm install tinseth


var tinseth = require('tinseth');
tinseth(og, boilSize, postBoilVolume, aa, amount, time); // -> IBUs for this hop addition 


  • og the expected OG of your brew
  • boilSize the amount of the wort at the start of the boil (in liters)
  • postBoilVolume the amount of wort at the end of the boil (in liters)
  • aa the alpha acid percentage of the hop, a number between 0.0 and 1.0
  • amount the amount of hops in this addition (in grams)
  • time the duration this hop will be in the boil for (in minutes)
  • maximumUtilizationValue optional the maximum utilization value. Defaults to 4.15. From How to Brew: "This number may be adjusted to customize the curves to your own system. If you feel that you are having a very vigorous boil or generally get more utilization out of a given boil time for whatever reason, you can reduce the number a small amount to 4 or 3.9. Likewise if you think that you are getting less, then you can increase it by 1 or 2 tenths."