What the Heck is a "Hop Storage Index"?

[whovous]

More important, what do I do with the Hop Storage Index?

I want to try to clone a new commercial brew tomorrow. I know which grains and hops are used, as well as the ABV, IBU and SRM numbers. I've come up with a grain bill that BrewSmith tells me will match the original ABV and SRM numbers.

I am using newly purchased 2014 crop Hop Union hops in one oz bags that I assume have been well tended by my LHBS. I thought I had my IBU ducks in a row until I noticed the line for "Hop Storage Index" in Brew Smith.

It says:
Mosaic: 25% Alpha/6 Months
Simcoe: 18% Alpha/6 Months
Columbus: 40% Alpha/6 Months

What, if anything, should I do with this intelligence? Do I need to change any part of my hop bill to get to the target IBUs? Or should I simply trust BeerSmith to solve that problem for me? I have already updated the Alpha acid percentages to those shown on the labels of the bags that I bought.

I want to match the numbers of the commercial brew as well as I can. How should I account for the year old hops in my equation?

 

[whovous]

OK, the BeerSmith blog says this:

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For example a hops with a starting alpha of 10% and HSI of 25% stored for 6 months would lose 25% of its alpha potential, resulting in an new alpha rating of 7.5% if stored at 68F. The same hops stored for 6 months at 28F (-2C) would only lose 10% of its alpha acids leaving it at 9% alpha content. To see sample HSI ratings for various hop varieties, visit our Hops Listing and click on the hop variety of interest. The HSI is on the detailed page for each hops near the bottom.

The HSI does not tell the whole story however. Hops will age at a much slower rate if stored in cold temperature and in a proper container. BeerSmith has a Hop Aging tool (Tools menu) you can use to calculate a particular variation of hop packaging, temperature and age, and also has the HSI in its hops database so you can just pick a hop variety, set your storage conditions and calculate the resulting alpha.
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I am going to assume these hops were well stored throughout their packaged life and simply ignore the index. It looks like if I do have a problem, it will be mostly with the Columbus, my sole 60 minute hop.

 

[IslandLizard]

In theory... yes. In practice... maybe not so much. Too many unknown variables.

I think the weakest link lies in storage at the LHBS in a 38°F fridge. OK for a few weeks, but not so if they've been there for several months or even longer. Frozen is the way to store them long time, the colder the better. This aside from them being in an as-much-as-possible O2-free environment such as an oxygen barrier bag, either N2 flushed, vacuum sealed, or at least purged from most air.

I still have hops I bought in late 2012, likely from the 2012 harvest. Some maybe even from the 2011 harvest, coming to think about it. They have been stored in a deep freezer at -4 - 0°F since I received them. They are about as potent as they were when I got them. Going by sheer %AA it doesn't taste like they've slipped much at all. At brewing time I compensate by adding 10% of weight per year of age, and find my beers coming out a bit more bitter than calculated as such. Flavor and aroma are still great and as expected, speaking of a nice, qualitative factor there!

 

[whovous]

I want to think the Hop Union packages are pretty close to 02-free.

As for my LHBS, you are right. We just don't know. I know they are well regarded, I know that they sell a fair amount of product, and I know that my hops (Mosaic, Simcoe and Columbus) are all pretty good sellers. I want to assume the best from all of that.

Also, my recipe calls for a fair amount of Mosaic and Simcoe at 5 minutes, at whirlpool, and a dry hop. I want to think that the pure volume of hops, most of which do not add to IBU per BrewSmith, will cure all sins for those hops. I bitter with Columbus, and I don't want to add to my 60 minute charge just because my bitterness might be a little light.

I am trying to clone Knee Deep Brewings Breaking Bud. It is not overly harsh on the tongue and I am content to let mine err on the side of even less bitterness.

 

[IslandLizard]

Agreed, HU hops are good quality and their bags are N2 flushed and filled. 2014 means they are a bit over a year old now, and warehouses should have stored them at or below freezing temps. Many East Coast LHBS get their supplies from BSG, which I'm unsure of how they actually store their hops, but we should be confident they follow common trade practices.

Nikobrew describes their storage and repackaging methods as follows, which seems to be common:

Domestic hops are harvested in September, pelletized, then put into 44 pound mylar bags with a nitrogen flush. They are then stored at temps well below freezing until we repackage them into smaller increments to ship to you. [...]

Popular hops tend to rotate quickly, you should be fine.

Now no matter how close a recipe you have to the original, process is the much bigger variable. Don't expect your first attempt to come out as a true clone. It will take some recipe honing and rebrewing to get closer. Read up on modern IPA brewing using long hopstands/whirlpools at lower temps with 2 or more hop additions.

BTW, maybe you should consider buying hops by the pound...

 

[whovous]

BTW, maybe you should consider buying hops by the pound...

Well, the pound of 2015 Mosaic I ordered from Yakima Hops reached my office on Friday, only shortly before the blizzard commenced. I was already bundled up at home. I need to learn how to factor blizzards into my hop buying.

Then there is the pound of Citra and Mosaic I've had on order from Label Peelers for seemingly forever...

I really wanted this one to be fresh as all get out, as I think this style really calls for it. I understand my process in a 24L pot just might vary slightly from that at the brewery

 

[k1ngl1ves]

Is this a competition brew?

If not...


I'd brew the recipe exact, without compensating for the hop age. When it's complete and carbed... taste it! Write everything down, and use it for future reference.

IBU's can be tricky. The only time you know for sure how they've been stored is when they're in your possession. What was dead on once, may not be so the next time you buy them. Usually close, but occasionally a crap shoot. Best bet is to not get so worked up about AA's. Brewing is a hobby, so keep it fun and experiment!

 

[whovous]

No, it is not a competition brew. I think I am getting good enough where a competition might teach me something, but right now is not the time.

I had Knee Deep's Breaking Bud on a trip to NYC over New Years and was sufficiently blown away that I want to clone it. It is a pretty new release, so Google has not provided a great deal of help. I think I am closer than the other two recipes out there, but who knows what my process will produce?

The really bad part of this whole experiment is that Breaking Bud is not sold in DC, so I will probably not have the original to compare when I finally sample my work. I doubt that will stop me from drinking it, however.