Author Topic: FWH IBU calc  (Read 8042 times)

Offline nostalgia

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FWH IBU calc
« on: August 02, 2009, 09:36:44 PM »
Evening!  I've seen a few threads on FWH calculations, but none seem to match what I'm seeing here.

I've got a recipe that has two hop additions for 17.8 IBUs:

1.00 oz Fuggles [4.00 %] (60 min) Hops 12.9 IBU
1.00 oz Goldings, East Kent [5.00 %] (8 min) Hops 4.9 IBU

Now I'd like to change the Goldings to a FWH addition.  So I change the 'Hop Use' to 'First Wort' and the boil time to 60 minutes.  The IBUs jump to 30.7!

Then I read something about FWH's IBU impact being 10% more than a 20 minute boil.  Ok, a 20 minute boil on the Goldings brings my IBUs to 22.7.  10% more than that is still only 24.5 IBUs.

So how is Beersmith calculating 30.7?  I checked in my options, and my FWH adjustment is 10%.

Thanks,

-Joe

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Re: FWH IBU calc
« Reply #1 on: August 02, 2009, 10:04:30 PM »
Joe,
  First wort hops is added at the very beginning of the mash runnings, and therefore the hops remain in the boil throughout the entire boil time - which is why they added such a large amount of bitterness.

  Boiling for 60 minutes adds a lot more bitterness than boiling for 8 minutes.  To compensate you can use less hops than you did before.

Cheers,
Brad
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Offline nostalgia

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Re: FWH IBU calc
« Reply #2 on: August 02, 2009, 10:12:21 PM »
Maybe I wasn't clear in my question.  I'm trying to figure out what Beersmith calculates the 10% against, since none of the calculations above make sense.

If I make the Goldings hops a 60 minute boil, that brings my IBUs to 29.1.  10% more than that is 32.  I'm still confused about where the 30.7 is coming from.

Also much of the reading I've done suggests just moving the aroma/flavor hop addition from the end of the boil to FWH and not changing the quantity.  How is that possible if it's doubling the IBUs?  Even if the bitterness perception is "smoother and more balanced" as many report, a doubling of IBUs has to completely change the character of the beer.

-Joe

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Re: FWH IBU calc
« Reply #3 on: August 03, 2009, 06:46:37 AM »
Joe,
  The 10% is added to the normal calculation for a hop addition boiled that long.  If you take out the fuggles, the FWH addition of the Goldings for a 60 minute boil should be 10% more than without the FWH option set.  The key here is that the hops remains in the boiler for the full boil when using FWH so you do need less hops than with a finishing hops.  The FWH is not a direct substitute for a finishing hops.

Cheers,
Brad
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Offline MaltLicker

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Re: FWH IBU calc
« Reply #4 on: August 03, 2009, 07:48:02 AM »
Joe - the other setting that affects this math is the hops utilization model used, also under Tools\Options\Bitterness.  Using the BS's default of Tinseth, I duped your numbers using the same hops you entered.  (I fudged batch size and OG to get close enough.)  I got 13.0 IBU on the Fuggles and when I made it FWH instead, it moved up to 14.3 (13.0 plus 10%, or 1.3 = 14.3).  As an aside, any time we are copying a recipe it helps to know the hops model they used b/c each model uses different assumptions and reaches different forecasts for the total IBUs. 

Making the 8-minute addition a FWH addition also calculated correctly for me, moving from 4.9 to 5.4; however, as Brad said, FWH are added with the first runnings and are boiled at least as long or longer than the boil time.  (So an 8-minute FWH addition is not really a logical entry for BeerSmith.) 

I FWH a lot.  I have actually changed my FWH setting to be zero, because I've found the bittering to be much smoother, so while the IBUs may actually be higher, they do not taste higher nor seem as harsh, so some of my beers have been perceived to be low on IBUs when I've done 100% FWH. 

So I now have my FWH set at zero bump-up, and I usually have a small portion of the bittering hops as a regular 60-minute boil addition. 

Offline nostalgia

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Re: FWH IBU calc
« Reply #5 on: August 03, 2009, 08:48:14 AM »
I FWH a lot.  I have actually changed my FWH setting to be zero, because I've found the bittering to be much smoother, so while the IBUs may actually be higher, they do not taste higher nor seem as harsh, so some of my beers have been perceived to be low on IBUs when I've done 100% FWH. 

So I now have my FWH set at zero bump-up, and I usually have a small portion of the bittering hops as a regular 60-minute boil addition. 
So are you saying what I noted above: in your experience if you move the aroma/flavor hops to FWH without changing their quantities, you perceive a similar bitterness level, even though the IBUs appear to be obscenely higher in the recipe calculation?

Or are you reducing the amount of hops you use?

Thanks to you both for the thorough replies,

-Joe

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Re: FWH IBU calc
« Reply #6 on: August 03, 2009, 12:51:58 PM »
Honestly, I've never understood it when people say FWH are like a 20-minute addition, b/c I boil a FWH addition for probably 70 minutes.  That's a huge difference (3X?) in hops utilization under any hops model. 

From my experience, putting my 60-minute bittering addition in early, as FWH, lets them steep with the initial mash run-off at approx 150F for 15-30 minutes while the lautering is done.  The theory and my experience thus far is that this steep-time at milder temperatures creates hop flavor compounds that are more stable and that do not boil off as easily.  I think the bittering iso-alpha compounds are also smoother and less harsh. 

So for me, I just make my bittering addition a FWH one, and then flavor and aroma hop as I would otherwise.  As I said I'm tinkering with how to set the FWH adjustment.  I set it to zero at the same time I moved outside over propane, so my utilization has changed too.   This could be splitting hairs b/c I've also read that many people cannot distinguish differences of less than 10 IBUs, so we'd have to be talking a true hop bomb for the FWH adjustment to be 10 points. 

Below is a typical FWH recipe for me.  72% of the hops are FWH, and then I hop 60, 10 and 3 for bittering, flavor and aroma.   The total IBUs are high for a blonde ale, but they should be smoother.  Plus, I making the water "balanced" rather than "hop-centric" with more sulfate.   (This is an "el cheapo" brew I'm doing to figure out my water math and how slow I can lauter on the new system outside.  Base grain, hops, and dry yeast.) 

Style: Blonde Ale
Recipe: 6B Blonde Ale   TYPE: All Grain
---RECIPE SPECIFICATIONS-----------------------------------------------
Est IBU: 36.5 IBU      IBU RANGE: 15.0-28.0 IBU
Est BU:GU: 0.695   

---WATER CHEMISTRY ADDITIONS----------------
Chalk 0.0; Gyp 0.0; CalChlr 1.0; Epsom 1.5; Soda 0.0
C:S = 0.82 balanced.

---SPARGE PROCESS-----RECYCLE FIRST RUNNINGS !!
Add first wort hops during sparge
Amount        Item                                      Type         % or IBU     
1.00 oz       Glacier [5.90 %]  (70 min) (First Wort HopHops         26.4 IBU     
Sparge with 5.43 gal of 168.0 F water.

---BOIL PROCESS-----------------------------
Est Pre_Boil Gravity: 1.047   Est OG: 1.053 SG
Boil Ingredients
Boil         Amount       Item                                      Type         
60 min       0.25 oz      Glacier [5.90 %]  (60 min)                Hops         6.6 IBU
10 min       0.25 oz      Glacier [5.90 %]  (10 min)                Hops         1.3 IBU
3 min        0.50 oz      Glacier [5.90 %]  (3 min)                 Hops          2.2 IBU

Offline MaltLicker

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Re: FWH IBU calc
« Reply #7 on: September 15, 2009, 07:10:41 PM »
So for me, I just make my bittering addition a FWH one, and then flavor and aroma hop as I would otherwise.  As I said I'm tinkering with how to set the FWH adjustment.  I set it to zero at the same time I moved outside over propane, so my utilization has changed too.

An update on this.  I just bottled this blonde and it's great.  Per BSmith, the IBUs came in at 28.9, just at the high end for the style, but half the IBUs are FWH, and the bittering is smooth and flavorful, so it works.  I had also made the chloride:sulfate ratio "balanced" to not emphasize the hops.  The FWH setting was zero for this beer.

Thomas Creek Brewery came to our last meeting and said they FWH a lot; however, they said FWH actually decreased bittering by 10%, rather than increase it by 10%, which is the default setting in BSmith.  This actually makes sense to me, because the FWH are smoother and less harsh, so it makes sense the "perceived" bittering would seem to be less, and not more.  The lab analysis IBUs might be higher, but perhaps the taste/sensory IBUs are lower? 

I just brewed a hefe with a FWH setting of minus 10 and the IBUs are calc'd at 15.4, or the high end of that style too.  I'll see if that perceived IBUs is slightly higher since I told BSmith to discount it by 10%.  If it seems a tad sharp for a hefe, I may move it back to zero. 


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Re: FWH IBU calc
« Reply #8 on: September 16, 2009, 06:34:11 AM »
Hi,
  This has been a raging debate for some time across several forums and articles I've seen.  In general, FWH actually slightly increases the measured bitterness (in the limited experiments done), but also reduces the customer's perception of sharp bitterness - most taste testers report that the bitterness and beer is smoother than the non-FWH case.

  See my article on FWH on the BeerSmith blog for more info:
  http://www.beersmith.com/blog/2008/03/17/the-first-wort-hop-beer-brewing-techniques/

Brad
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