How do you calculate IBU for hopstand hopping? I understand that at temperatures below 79 degrees Celsius, hop utilization (isomerization) drops to 10%, but the brewness calculator seems to calculate as if I were boiling the hops for 15 minutes. I’m creating a recipe for a West Coast IPA, and when I enter 120g of Nelson Sauvin for hopstand, it gives me a huge IBU.
Here’s how I do it. Spreadsheet available for download.
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Thanks, Dave!
Here’s an article that I’ve found really useful - An Analysis of Sub-Boiling Hop Utilization - An Analysis of Sub-Boiling Hop Utilization | alchemyoverlord
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I get wildly different whirlpool/hopstand IBU contributions from BeerSmith, Brewer’s Friend, and BrewFather vs Dave’s spreadsheet. Of course, I could definitely be misusing the spreadsheet.
Brew the beer, taste it, and see which one(s) are closer to the truth, and which one(s) are way off. Do this with multiple different recipes to get a better feel.
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Use Brewers Friend calculator. Select whirlpool on hop selection use, change utilization from 5% to 3%. I find this be very accurate. I typically let it stand for 20 minutes, but it doesn’t seem to matter much if it’s 15 to 30 minutes, the results are the same.
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So go with empiricism, in other words? I’m all for that.
IMO brewers should ignore spreadsheets and other tools that tell them what they should be experiencing, and instead pay more attention to what they are actually experiencing.
I’ve read many posts to the effect of, “this spreadsheet tells me I should be getting (insert number) for this variable, but I am not, so I must be doing something wrong!”
If you are making beer that you enjoy drinking, you are doing nothing wrong.
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So true!!! Unless you have several of your beers lab tested you have no idea what the true utilization is. Daniel’s Designing Great Beers had a hop utilization curve based on several measurements. I used to use that but my brewing software I use now does not allow custom utilization as far as I know.
So you pick a utilization curve and see if your beer seems reasonable based on a known commercial sample knowing that carbonation and other factors can impact the perception of bitterness.
Yeah, I know. But when I make recipe for a beer which I will send to a competition I have one chance. I dont have enough time to brew couple time and compare a results. In this case I want to brew session west coast ipa with huge amount of Nelson Sauvin. I want to achieve a bitter beer and I want to use a lot of hops on hopstand. I thought that using hops under 78 Celsius doesnt increase IBU so much. My plan is IBU about 60 but with high AA% Nelson Sauvin on hopstand calculator show me IBU circa 150.
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For insurance then, why not take the hopstand temperature down to like 68 C instead of 78-79 C? Isomerization will be pretty slow at that point. Not zero, but less than the calculators, but you’ll still get plenty of flavor and aroma.
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IBU is a very narrow measurement of what is extracted from hops, specifically iso-alpha acids. For an already highly hopped beer with lots of late additions, I’d argue that the extra 10-20 estimated IBU is not only wrong, but irrelevant.
Its good idea and i will do this.
IBUs only become irrelevant after you hit the solubility ceiling of about 90 IBUs. If not hitting that ceiling, every hot hop addition matters. Unless your palate has grown increasingly immune to the IBU, which is also definitely a thing.
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Alpha acid solubility also decreases as IBUs increase, not just at the upper limit. It may matter for a Pilsner, but for a West Coast IPA I’d focus on what you want for flavor and aroma with the hop stand because I don’t think you’re going to taste the additional bitterness. YMMV, it could also be my burnt out palate!
Also, I think there is definitely a perceived bitterness that is different from lab tested IBU. Much like bitterness balances residual sweetness, a beer with more late hops (and therefore more hop oils and derived compounds) will be perceived differently than a beer of the same measured IBU but no late additions. If you lower your bittering IBU too much to compensate for the whirlpool hop addition, your beer may end up being perceived as more New England IPA and less West Coast.
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In the end, it’s only perception that matters. Whether its going to competition or not, no one knows what the actual IBUs are without a lab analysis. If it tastes as intended then that’s good.
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