SHOULD you adjust the Hops AA%?

[makemorebeer]

I've been brewing for a few years now, and one thing I've never done is adjust my hop AA% on my recipe to match the AA% on the Hop packaging.  I've been doing some reading, and the method i'm looking to use is to adjust the AA% in recipe, then bump up the IBU slider to match the recipe specs. 

My question is, should I bother or is the difference imperceptible?  Is there a better way, aside from doing longhand on each of the contributions?

ex.   the batch i'm brewing tomorrow has...
1oz Willamette @60 AA%=5.5, Actual AA%=4.1
.5oz Fuggles @45 AA%=4.5, Actual AA%=5.6
.5oz Willamette @30 AA%=5.5, Actual AA%=4.1

Software calculated my IBU at 29.3

Thanks in advance

[brewfun]

In the under 50 IBU range, +/- 5 IBU is detectable to most people. It'll effect the balance and repeatability of the recipe.

That said, the main reason for using BeerSmith is to make accurate predictions about all of your batches and help you see what's changed over time (in the brew log). So, it's always good to maintain accuracy if only to help your future self remember what happened.

[makemorebeer]

So what i'm taking away from that is, yes you should if you care about repeat-ability, and in this recipes case, keeping the same profile.  So, is the method I'm talking about in my OP what others here would do then?  or is there a better way?  i'm going to go ahead and make those adjustments before i brew in a few hours.

[BOB357]

I'm with brewfun 100%. When adding hops to my inventory I enter the AA% listed on the package as well as the date purchased and the source. Some varieties can vary quite a bit from crop to crop, and even from field to field. I also keep information updated for yeasts and grains.

When rebrewing a beer I want consistency. If brewing a beer for the first time, whether my own or someone else's recipe. I want to have a baseline to work from that's as accurate as possible.



 

[dtapke]

those differences would likely give you a difference around 5ibu which would likely be noticable.

not knowing the style or rest of the recipe, this could put you out of the ibu range for the style. it could also lead to a beer thats out of balance (too sweet)

5 gallon batches (i'm assuming here..) are VERY easy to mess up due to the small volumes you're working with. youll note that the difference between 1oz on your 60 minute boil and 1.1 oz will likely give you 1 extra ibu alone, and thats only a difference of a tenth of an ounce.

so, I'd say if you want to brew consistently good beer, being as accurate as possible is key. especially in small batches like that.

once you start brewing 10G batches or like me 30g batches, making those AA changes becomes an absolute need, as the difference between a pound of hops with an AA of 4.5 and a pound of hops with an AA of 5.5 becomes pretty huge.  (just checking, i played with a recipe quickly and it was a difference of 30ibus on one of my existing recipes! thats HUGE!!!)


TL;DR YES ABSOLUTELY CHANGE IT!

[bougie1st]

Just my 2c

Agree with the above - adjusting the AA% will help you nail your IBU for reproducibility. However, you have to also consider the impact of changing the amount of hops on other flavours, particularly late boil additions.

For example, I did a Belgian Blond ale with 30g saaz (beginning) and 30g styrian toward the end. On changing the AA%, I had to bump the quantities to 50g each (big difference). As a result, the beer was too 'hoppy' from the larger late hop addition.  After giving it even more time to age than usual, it did settle down (and was delicious, might I add).

In future, I will use 30g of each, but supplement the bittering charge with magnum (clean, neutral bittering) to reach my IBU, but maintain the appropriate hop flavour balance

[Oginme]

Boogie1st brings up a good point.  I always adjust the %AA of my hops to reflect my current inventory.  Using the inventory, I can duplicate and note the different lots of hops giving me the ease switching lots when I run through one lot and start the next. 

Doing this blindly, however, can really throw you off when it comes to large additions of low alpha hops.  As an example, I brewed by first Czech pilsner with Saaz hops at 4.1% AA.  Turned out pretty good but maybe a bit light on the bitterness to my taste. When I went to repeat that recipe my lot of hops had a AA of 2.6%, nearly doubling the hop loading.  Two take-aways: (1) if I had not changed the %AA of the hops, I would have beeen even more lacking in the bitterness which needed to be increased; (2) the increase in hop matter very much affected the ending taste providing bit more in vegetal backing flavors. 

To balance this out, I switched to bittering with a base load of Magnum combined some of the Saaz hops to provide the flavor profile from the early addition.   Now if the %AA changes drastically, I can choose to adjust the Saaz hops in the later additions to suit, but only need to adjust the Magnum to supply the change in bitterness level. 

[makemorebeer]

Thanks everyone. 

i was wondering about the late hop additions, but this particular recipe didn't really have any.  in the end it's a Bourban Barrel NutBrown, so the hops should probably play very little into the flavor profile.  BUT, this is also a friends recipe converted to AG from Partial, so we're not real sure what she's gonna taste like yet  

in the future i'll be making the AA% adjustments.  there just isn't really a reason not to and repeat-ability is very important to me as i gauge my skill level on this. 

[dtapke]

Many breweries actually do their late hop additions based on weight alone (whirlpool and dry hops) there's another thing to think about