HOPS calculating correct AA

[Allan Siegle]

I came across a Hops calculator that after you put in the info about the hops
Age
Type of storage
Storage temp
Alpha Acid percentage
It will calculate the current Alpha Acid that you can input in your brew software. I’m wondering if anyone has use it and if it is helpful?

http://brewerslog.appspot.com/HopAlphaCalc

 

[Vale71]

Substitute "calculate" with guesstimate and you'll get closer to the actual truth...

IBU calculations are at best an educated guess, often off by as much as 100%. Add hop aging estimation and you've basically got and estimate based on another estimate.

 

[dmtaylor]

It's junk. In my own experience hops will maintain alpha much much better than anyone estimates.

 

[Robert65]

estimate based on another estimate.

That's what seems to pass as science these days!

Seriously, all these calculations put out for homebrewers are junk. They are based on even less than an estimate.

But even if the calculations were accurate, it would not necessarily be significant, because your palate cannot distinguish differences of IBU finer than about +/-5 at best.

Just add hops. If you don't like the resulting beer, adjust the recipe based on that solid, empirical, evidence the next time.

 

[Silver_Is_Money]

It's junk. In my own experience hops will maintain alpha much much better than anyone estimates.

I store my hop pellets in a deep freezer, and I've gotten several years of use out of them without noticing a decrease in AA's (not that it isn't there to some degree).

 

[dmtaylor]

I store my hop pellets in a deep freezer, and I've gotten several years of use out of them without noticing a decrease in AA's (not that it isn't there to some degree).

Might lose 5-10% after several YEARS in my experience, that's all.

 

[Allan Siegle]

Might lose 5-10% after several YEARS in my experience, that's all.

Meaning if the AA percentage is 13 then end up being 3-8% ?

 

[Silver_Is_Money]

Meaning if the AA percentage is 13 then end up being 3-8% ?

No, it winds up being about 12.3 to 11.7 AA's.

 

[mabrungard]

Agreed. I keep my hops in the freezer and I find they perform at the stated alpha for years.

 

[Silver_Is_Money]

Wow, the calculator linked within the OP's 1st post says the ~3 year old Magnum hops in my deep freezer have lost ~88% of their original AA's. When I stated that the recipe called for 1 Oz., it indicated that I must instead add 8.3 Oz. to compensate for AA loss.

Not if I'm the one drinking it. I'd still add 1 Oz.

 

[Allan Siegle]

Then I hit 2 beers that are gunna be super hopped!!!

 

[dmtaylor]

The nice thing about overhopping is that there is a ceiling of about 80-90 IBUs no matter how much hops you use, so you can always call it a pale ale or IPA.

 

[Denny]

Might lose 5-10% after several YEARS in my experience, that's all.

so you had the beers analyzed?

 

[Denny]

We interviewed Glenn Tinseth for Experimental Brewing. He said that unless you use the exact same equipment he did when he developed the formula, and you brew exactly the same including chilling time, there's no reason to think that any IBU calc is accurate. Not to mention that it was developed with whole hiops, so if you use pellets it's even farther off. We then did an experiment that seems to confirm it.

https://www.experimentalbrew.com/experiments/writeups/ibu-lie-kind

https://www.experimentalbrew.com/podcast/episode-32-ibu-lie

 

[Denny]

The nice thing about overhopping is that there is a ceiling of about 80-90 IBUs no matter how much hops you use, so you can always call it a pale ale or IPA.

Taste threshold, not measurement

 

[Denny]

Agreed. I keep my hops in the freezer and I find they perform at the stated alpha for years.

Have you had any tested to confirm that?

 

[Robert65]

Have you had any tested to confirm that?

Tasting the beer is a pretty good test of what the hops are contributing. Cheap, easy, and fun test to perform, too.

 

[Imhoppy]

Tasting the beer is a pretty good test of what the hops are contributing. Cheap, easy, and fun test to perform, too.

Agree. That's better than calculating an exact estimate. [emoji481]

 

[dmtaylor]

so you had the beers analyzed?

By my taste buds, yes. Which I trust to a fault.

 

[dmtaylor]

Taste threshold, not measurement

Both. You can have >100 IBUs in the boil, but many of the IBUs settle out before you get it into your glass, that's reality.

https://www.masterbrewerspodcast.com/123

 

[Denny]

By my taste buds, yes. Which I trust to a fault.

Fault being the key word...

 

[Denny]

Both. You can have >100 IBUs in the boil, but many of the IBUs settle out before you get it into your glass, that's reality.

https://www.masterbrewerspodcast.com/123

Settle out? Explain please.

 

[Denny]

Tasting the beer is a pretty good test of what the hops are contributing. Cheap, easy, and fun test to perform, too.

Maybe, maybe not.

 

[Denny]

Agree. That's better than calculating an exact estimate. [emoji481]

But not nearly as good an as analysis

 

[Robert65]

Settle out? Explain please.

Well, I know it's a commercial brewers' rule of thumb that at most 75% of BU recovered in the wort at knockout will pass through to the finished beer. The main factors are that more iso-alpha acids (and other bitter substances) are soluble in hot wort than at colder temperatures (a major constituent of trub,) and that a significant portion of the iso-alpha etc. will bind to yeast cells and settle out. This effect also depends to some degree on the yeast strain, specifically cell and floc size. Strains offering more surface area in a given biomass (that is, often, powdery or less flocculant, more attenuative yeasts) can adsorb and remove more bitter substances. Fining and filtration can also significantly reduce BU.

 

[dmtaylor]

Settle out? Explain please.

+1 @Robert65 , who speaks more eloquently than I. And, maybe listen to that podcast linked above when you have a chance.

 

[BrewnWKopperKat]

I came across a Hops calculator ...

Looks like the original calculator was announced here (back in 2012):
https://www.homebrewtalk.com/forum/threads/old-hops-aa-calculation.330373

"Brewing Techniques Magazine was published from 1993 to 1999 (link) ... In 2012, MoreBeer purchased the entire back stock of printed magazines. Those are available in the Homebrewing Books & Magazines section of MoreBeer’s website.".

A web search on the author / title lead to https://www.coursehero.com/file/16936036/Hop-Storage/, which suggests that the article that may have been used for the calculations was published in the Jan/Feb 1994 issue of the magazine.

A careful read the of the JavaScript code and the article would confirm both the source and the accuracy of the implementation of the equations. Note that this doesn't address the accuracy of the equations in the article.

For something that's known to be newer, https://www.masterbrewerspodcast.com/123 is worth a listen.

 

[Denny]

Well, I know it's a commercial brewers' rule of thumb that at most 75% of BU recovered in the wort at knockout will pass through to the finished beer. The main factors are that more iso-alpha acids (and other bitter substances) are soluble in hot wort than at colder temperatures (a major constituent of trub,) and that a significant portion of the iso-alpha etc. will bind to yeast cells and settle out. This effect also depends to some degree on the yeast strain, specifically cell and floc size. Strains offering more surface area in a given biomass (that is, often, powdery or less flocculant, more attenuative yeasts) can adsorb and remove more bitter substances. Fining and filtration can also significantly reduce BU.

Sorry, I don't buy it. Analysis of my beers doesn't seem to bear it out.

 

[dmtaylor]

Too bad we don't all have easy access to laboratories.

 

[Robert65]

Sorry, I don't buy it. Analysis of my beers doesn't seem to bear it out.

But the analyses done by breweries tracking every batch, dozens a day, for decades, in their own labs, do establish it. More data points needed?