How Accurate Are Calculators for IBUs?

[Tobor_8thMan]

Oh they were definitely in the freezer. The issue is that home model vacuum sealers and vacuum bags aren't 100% with hops. The oils and dust prevent a perfect seal. Jars work better but take up more space.

If hops are opened once and immediately resealed and the seal holds, probably less of an issue. The more/longer they're opened and if the seal doesn't hold (constant problem I had with FoodSaver sealer/bags), that's the issue.

Well, I simply double freezer bag mine and have had zero issues. You are in Arlington, VA. Willing to take a trip to Manasass, VA to simple my homebrew. I welcome your visit.

 

[BSheridan]

Thanks for the input guys. If beer smith is saying around 50, brewers friend is saying around 70 and the recipe sheet that came with the kit is saying 60, hopefully it ends up somewhere right around that 50-60 mark. I'm just going to follow the instructions and see how it turns out.

Hopefully the perceived bitterness will be relatively low and it'll be a nice brew

 

[Tobor_8thMan]

Sounds like Brewers Friend isn't taking something into consideration whereas the others are taking these into consideration.

Brew it and send a few to us for evaluation. That's a great idea!

 

[VirginiaHops1]

Sounds like Brewers Friend isn't taking something into consideration whereas the others are taking these into consideration.

Brew it and send a few to us for evaluation. That's a great idea!

I use brewersfriend and I've noticed many times the IBUs it calculates seem much higher than what people say Beersmith gives them. Not exactly sure why. The default AA % the sites use for each hop variety may differ but I wouldn't imagine that significantly.

 

[BSheridan]

I use brewersfriend and I've noticed many times the IBUs it calculates seem much higher than what people say Beersmith gives them. Not exactly sure why. The default AA % the sites use for each hop variety may differ but I wouldn't imagine that significantly.

I actually adjusted the AA% to match what is on the packaging for my hops and still got that high number. I'm just gonna brew it and see how it turns out and if I don't like it, I'll adjust the next time around

 

[Silver_Is_Money]

When I stated that IBU calculators will "typically" get you to within +/- 35% of reality I should have stated that odds favor your actual IBU's (as tested by a lab) falling somewhere to the low side of software projection much more often than to the high side of this +/- 35% range.

In addition, all of these calculator formulas predate (or at least never considered) pellets, so Tinseth himself once stated that for pellets "all bets are off". I for one believe that he meant it.

 

[VirginiaHops1]

I actually adjusted the AA% to match what is on the packaging for my hops and still got that high number. I'm just gonna brew it and see how it turns out and if I don't like it, I'll adjust the next time around

I think that sounds like a plan. IBUs in the 70s isn't that bitter for me, but everyone's tastes are different. Plus perceived bitterness depends on more things than just IBUs. Best way to dial in your recipes is just do it then do it again.

 

[cactusgarrett]

As BobBailey suggested, it's all about perceived bitterness. When designing recipes, I personally pay attention to the IBU/SG ratio. For example, your theoretical IBU of 70 for this given recipe could be perceived as very bitter if your OG is something like 1.040. Conversely, if it were 1.070, you'd have a lot less perceived bitterness.

This concept is well displayed with barleywines, which are often in the ballpark of 100 (theoretical) IBU, but have minimal perceived bitterness due to their high gravity and malt profiles.

 

[BSheridan]

Brewed it this weekend. Its sitting in the fermenter as we speak. OG came out at 1.055 which is actually a couple points over what the recipe estimate was. Dry hop next week and then packaging 5 days later. Will update this thread with how it comes out