Correct AA when buying hops?

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SethMasterFlex

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Hey all. I've bought hops in bulk a few times times now. Something that's been bothering when I've been formulating my recipes is whether or not the AA's reflected on the package are from the time of harvest, or do the hop distributors adjust that before they send it on over if I order later in the year.

For example, I ordered 8 oz of Simcoe in February that had a listed 12.7%AA. Is this an adjusted alpha for what it should be after having been harvested and sitting around for 4 or 5 months, or was this the alpha at harvest? Does this vary from producer to producer?

I order my bulk hops from freshops.com and they hand write the alpha in and don't list the actual alphas on their site, just AA ranges. (i.e. Simcoe might be 11-13%). Thanks.
 

broadbill

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I would be surprised if they adjusted it....I'm guessing the %AA listed is what the batch tested out at harvest.

I would think its pretty tough to estimate how %AA changes post-harvest and in storage.

I guess the real question is: does it change enough in post-harvest and storage to worry about it? I'm guessing the current storage conditions in use today (nitrogen flushed, barrier bags, cold-storage) are being used because its been shown to minimize changes in %AA levels.
 

Captain Damage

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There's an interesting interview here with Glenn Tinseth (yes, that Tinseth). While he does not address all your questions, he does say AA is measured by the wholesaler once, from a single sample of a 200lb bale. He goes on to say that variations of 10% or so are normal.
 

logan3825

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That's why it is called an estimate when calculating IBU's. Lots of unknown variables.
 
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SethMasterFlex

SethMasterFlex

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Awesome, very good info here. I can't listen to the podcast just now as I'm at work, but will give it a listen later. I know a lot more factors come into play like cohumulone levels that make ibu perception inconsistent from hop to hop (i.e. Amarillo is much less bitter than something like warrior if used in equal AAU's).

I'm currently designing an APA that I want every gram of hops to count without making the resulting beer overly bitter, so I'm just trying to be as consistent with numbers as I can, even if they can be somewhat misleading.
 

Captain Damage

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...I want every gram of hops to count without making the resulting beer overly bitter...
Keep in mind that while there are a lot of variables we're not even mentioning, the threshold of perception in a finished beer is 5 IBU - and that's for light/pale industrial American lagers (BMC). So while the uncontrollable variables are many, your ability to taste their effect is rather limited.
 
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SethMasterFlex

SethMasterFlex

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I guess that came out a little strong lol. Just meant I wanted to keep my bu:gu balance in check while still getting a nice and hoppy pale. I did get to listen to that podcast and I did pick up on the "don't worry about the exact preciseness of your numbers" bit. I'm a microbiologist by day so, sometimes, I tend to get a little crazy about exact data instead of just going with it. Besides, if the balance is off by a tad, I'll just have to brew it again :D
 

Captain Damage

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That's cool. I just meant don't let the things you can't control - or the things that are just too impractical to control = ruin the fun of brewing. The analysis of your hops is only out to one decimal place; your altitude will affect the temperature and vigor of your boil; the humidity on the day you brew will affect your evaporation rate; etc. BU:GU is key, I agree, but don't get too caught up in splitting hairs here either. E.g., if you're at 0.868 or 0.872, just call it "somewhere between 0.85 and 0.9." It's not just the issue that you probably can't taste the difference, it's that trying to "correct" for the difference by micro-measuring your hops (or whatever) when your hops were never even analysed to a level of precision that would make your adjustment accurate is a fool's errand.

According to Daniels, BMC brewers only control their bitterness to +/- 2 IBU (measured with a spectrograph). And that's when their target average is only about 15 IBU. For those guys consistancy is everything, and they allow a spread of 4 IBU.

RDWHAHB! :)
 
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SethMasterFlex

SethMasterFlex

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Thanks for the information and advice, I appreciate it and will be taking a more relaxed approach to this one.
 
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