I’ve been brewing several beers lately whose recipes call for late ,5,10 or15 min, hop additions. Most call for old world hops which have had a big drop in AAs the last few years. Matching the IBUs in Brewfather leads to almost triple the original recipes hops. The last Saaz I bought had 1.7% AA. I have been just going by the recommended volume instead. Am I correct doing this or should I match the small IBU given in BF? Is there a point in a 60 min boil when I should be matching volume vs IBUs?
I think you should be looking at the IBUs. But, you also need to be aware that the more hops you add, the more space it takes up, which means smaller yields.
I have designed my recipes so that my 60 minute addition is where I generate all of my IBUs. I’ve skipped 5,10, and 15 min additions all together and moved those hops to the whirlpool/flameout.
I’ve also changed my thinking when designing recipes. I brew 5 gallon batches at a time, but I design it as a 6 gallon batch. I end up with a little more beer than I can use - but I like giving space for trub, yeast, or dry hops and still end up 5 gallons of finished beer.
Late hop additions are not about IBU. They are more about flavor and aroma. I would stick with the original weights for late additions.
The quantity I’m talking about isn’t going to be that big a deal. Just aroma additions in European style beers. We’re not talking NEIPA here. I do already have BF set up for trub and fermenter losses.
I don’t think it’s one or the other. Later in the boil IBU is less meaningful. I think certainly at flameout it is all about weight, at 5 minutes it’s mostly about weight but i consider the IBUs, by 15 minutes I’m back to IBU.
I suggest using the weight from the original recipe for those late boil additions, and then adjusting the 60 minute addition to get the target IBU.
Personally, I shoot for IBU’s rather than weight for late additions. Yes, most are about aroma and flavor and add low amounts of bitterness to the beer. If you brew by the same weight with lower AAU hops for the final additions and end up say 4 IBU’s lower, you are still OK, you won’t taste it anyway, but you might notice a difference in flavor or aroma. That said, my goal is to be consistent every time which is why I match the IBU’s of the various additions when brewing.
Secondly, I no longer worry about volume of beer that goes into the fermenter. I brew for target gravity and bitterness and if i end up with a little less wort going into the fermenter, so be it. Again, consistency is the name of the game in my brewery.
Hope this helps.