Going by Northern Brewer I should be using 7.13 ml for 60 IBUS in a 1.080 OG at a 90 min boil for a 6 gallon batch.
Beersmith is saying to add 10 ml to get the same 60 IBU.
Just wondering why there's a difference.
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One thing I tried was to enter a recipe from Zymergy that has all the stats...