Stone Enjoy By DIPA Recipe Question

[najohns]

Sorry for the relative newby question, but I found the following clone recipe online, which is supposed to be a 90 IBU recipe (as is Stone's version), but when I plug this guy into Beersmith, the recipe is ~90 IBUs without the 10 mls of hop extract (which is ~90 IBUs itself). What's up here? I'd like to brew this, but I don't understand the hop shot addition. Thanks.

Brewed: 04-01-13
Dry Hopped: 04-09-13
Kegged: 04-16-13
OG: 1.082
FG: 1.012
ABV: 9.3%
IBU: 90
6 Gallons

8.25lbs English Pale Malt (3.5L)
8.25lbs 2-row
1lb Dextrose
Mash at 147* for 75min
Stone gives the exact hops they use. I substituted a few based on what I have, what I want to use up, and what I feel won't make a difference. You'll see the hop Stone uses in parenthesis.
2oz Belma (Calypso) - Mash Hopped
10ml Hop Extract @ 90min
1oz ea. Simcoe, Belma (Delta), Northern Brewer(Target), Amarillo @ 15
1.25oz ea. Citra, Cascade, Centennial (Motueka) @ Flameout
Whirlpool for 20min
WLP007 - Dry English Ale Yeast
Dry Hop 1: 1.5oz ea Nelson Sauvin & Galaxy
Dry Hop 2: 1.5oz ea Nelson Sauvin & Galaxy

 

[globe]

Just add enough extract to where it adds up to 90 IBU. So by my rough math without knowing your alpha acids is 3 to 4 ml of hop extract at 60 unless you really need to do a 90 min boil, or just add less at ninety but I am not sure of the measurement on that sorry.

I would lean to less hop extract since you are doing a whirlpool and that can add a few IBUs. Also FYI a lot of people on here don't like the hop extract....i can only describe it as "different", but i do not have any science to backup my claim so try for yourself, it is easy to use though.

 

[najohns]

Thanks. That's about what I figured too, but my question is really about the recipe itself. It doesn't make sense to me, but the forum I found it on had many people who replicated it and said it was great.

The late addition hops and whirlpool hops are ~90 IBUs by themselves, but if you add the extract at 90 minutes, the total IBUs for this recipe would be ~180 IBUs (according to Beersmith) .... which is not the 90 total IBUs the recipe description says it should be. This is what doesn't make sense to me. Any input here? If I want 90 IBUs, like the recipe (as well as the Stone version of this beer) is supposed to be, should I skip the 90 minute extract addition all together?

 

[sandyeggoxj]

Calculated ibu != measured ibu. Don't worry if you calculate up to 200. Doesn't mean anything. Brew that recipe. It is a great beer!

 

[stpug]

Stone probably reports actual IBUs and not calculated IBUs. It's said that the threshold for IBUs is 100 and that you will inevitably fall short of that after yeast flocculation. In other words, you could build a recipe that says it will have 9999 calculated IBUs and still the actual IBUs will be just short of 100 IBUs.

I would brew the recipe as the clone indicates and adjust in the future if you think it needs it.

 

[najohns]

Thanks everyone!

 

[AK7007]

]It's said that the threshold for IBUs is 100 and that you will inevitably fall short of that after yeast flocculation.

Is the threshold for solubility of isomerized α acids 100IBU? I know that's the theoretical detection limit of our taste buds, but I'm pretty sure that wort can hold and solvent extractions can detect higher concentrations, with diminishing returns on α acid extraction from the flower to the wort as the amount of hops used increases.

 

[stpug]

Is the threshold for solubility of isomerized α acids 100IBU? I know that's the theoretical detection limit of our taste buds, but I'm pretty sure that wort can hold and solvent extractions can detect higher concentrations, with diminishing returns on α acid extraction from the flower to the wort as the amount of hops used increases.

My understanding is that, yes, the threshold for solubility of isomerized α acids is ~100IBUs. Granted, I am neither the brewery nor the testing lab that have reported these results - just the homebrewer who has picked up on this information through his readings.

IIRC, there have been beers whose calculated IBU levels have been MUCH higher than 100 IBUs and, after lab testing, have had the tested values fall around the 100 IBU mark (sometimes falling just above 100 but not by much maybe 5-7 ibus).

I would be useful to find these sources again. I wish I had them handy to post right now but it'll take some investigation to find them again.

 

[AK7007]

I remember solubility being around 100ppm, but can't remember at all what the IBU translation is. I'll go google.

EDIT: IBU is just ppm. Stupid brewers.

 

[GRBC]

That recipe is from the awesome Bertus Brew blog. He talks in there (and in HBT) about the IBU cheat sheet that accompanies those 5ml hotshots as being BS, and so uses quite a bit more hop extract than others. I think his logic is sound.

 

[najohns]

That would explain the 10ml addition. Thanks GRBC.