[hopfenundmalz]

"When someone asks how many IBUs I say I don't know"

And when someone tells you how many IBUs, they don't know! 

IBUs are pretty accurate for th3 beers they were developed on. The clear lagers of the 60s, with one bettering addition.

[klickitat jim]

I start by deciding how much FWH I want to use (OK, you guys, don't start!  )  That usually is 1-2 oz.  Then I figure out how much to use at 60 min. to get in the neighborhood of the 1:1 BU:GU ratio Jess talks about.

Is that ratio guideline for total ibus? Or just the bittering additions?


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Not to speak for Denny but, usually when people reffer to GU/BU its total they are talking about. 1:1 would be like 1.060 to 60 IBU.

The trouble is when it comes to high dose whirlpool additions. The science might say that no isolmerization is happening below X temp, but our mouths still translate those additions as some level of bitterness, though zero IBUs. If anyone doubts that, do a batch with no boil hops, and about 3 ounces of Simcoe at 150F for 30 min. There will be some bitterness. So, like any other ingredient, sometimes we can totally reduce hops to a numerical matrix. But experience will tell you what you like, don't like.

The science from OSU says isomorization goes on below boiling. You get less as the temperature goes down.

Totally, its not an on/off switch at 212. Ive heard various %s at 190/180/170 but I've not been able to find how much at 150F or below.

[hopfenundmalz]

I start by deciding how much FWH I want to use (OK, you guys, don't start!  )  That usually is 1-2 oz.  Then I figure out how much to use at 60 min. to get in the neighborhood of the 1:1 BU:GU ratio Jess talks about.

Is that ratio guideline for total ibus? Or just the bittering additions?


Sent from my iPhone using Tapatalk

Not to speak for Denny but, usually when people reffer to GU/BU its total they are talking about. 1:1 would be like 1.060 to 60 IBU.

The trouble is when it comes to high dose whirlpool additions. The science might say that no isolmerization is happening below X temp, but our mouths still translate those additions as some level of bitterness, though zero IBUs. If anyone doubts that, do a batch with no boil hops, and about 3 ounces of Simcoe at 150F for 30 min. There will be some bitterness. So, like any other ingredient, sometimes we can totally reduce hops to a numerical matrix. But experience will tell you what you like, don't like.

The science from OSU says isomorization goes on below boiling. You get less as the temperature goes down.

Totally, its not an on/off switch at 212. Ive heard various %s at 190/180/170 but I've not been able to find how much at 150F or below.

Try and find Mark Molowicki’s master thesis from OSU.

Scott Janish got 2 IBU from a beer dry hopped at room temperature, HPLC measurements, it’s on his blog.

[klickitat jim]

Found the paper. According to the summary, the lowest they tested was 90C/194F.

[Robert]

I've frequently seen 180°F cited as threshold for isomerization, but who knows where that comes from.  My FWH is easily below that and I seem to get fullest possible bittering out of the addition even with short boils.  Just testing by taste buds.

[Big Monk]

Some of the calcs I’ve seen essentially take the OSU paper and use the findings to produce a modifier for the Tinseth Utilization value as follows:

Whirlpool Utilization = Regular Utilization * 0.6^((212-Whirlpool Temp (°F))/18)

EDIT: So say U is calculated at 0.125, and you whirlpool at 180 °F, U would be modified to:

0.125 * 0.403 = ~ 0.05

[Robert]

I think I can see the weeds from here, and a rabbit hole right in the middle....   

[klickitat jim]

Here's a quote that indicates what I am feebly trying to articulate. "One obvious result from this experiment is that IBU values can not be directly substituted for isomerized α-acid values, especially at short steep times, high hopping rates, and sub-boiling temperatures.  This is because IBU values reflect not only isomerized α-acid values, but also contributions from oxidized α and βacids and polyphenols."

Um, soooo lab measured IBUs contain more than just isolmerized alpha acids. Like I said, whirlpool hops do bring bitterness to the beer. More than an isolmerization chart will predict.

Saying that IBUs only come from isolmerized alpha acids is like saying high alpha hops are for 60 min additions and low alpha are for dry hopping. Ya, maybe a good starting point but keep experiencing and adapting to your experience

[Robert]

Here's a quote that indicates what I am feebly trying to articulate. "One obvious result from this experiment is that IBU values can not be directly substituted for isomerized α-acid values, especially at short steep times, high hopping rates, and sub-boiling temperatures.  This is because IBU values reflect not only isomerized α-acid values, but also contributions from oxidized α and βacids and polyphenols."

Um, soooo lab measured IBUs contain more than just isolmerized alpha acids. Like I said, whirlpool hops do bring bitterness to the beer. More than an isolmerization chart will predict.

That's what Jeff was getting at with his remark about 60s light lager.  BU was developed at a time when they assumed degraded hops, with lots of beta acids oxidized to solubility, and brewhouse procedures that extracted more of other bitter substances from grain and hops.  The relation to iso-alpha is tenuous.

EDIT  _The Practical Brewer _ (MBAA, 1977) indicates in exemplary analyses that BU is about 1.15x iso-alpha acids.

[klickitat jim]

I imagine the 2005 OSU study used fresh hops though. By oxidized alpha and beta, I dont think they mean stale.

[hopfenundmalz]

Here's a quote that indicates what I am feebly trying to articulate. "One obvious result from this experiment is that IBU values can not be directly substituted for isomerized α-acid values, especially at short steep times, high hopping rates, and sub-boiling temperatures.  This is because IBU values reflect not only isomerized α-acid values, but also contributions from oxidized α and βacids and polyphenols."

Um, soooo lab measured IBUs contain more than just isolmerized alpha acids. Like I said, whirlpool hops do bring bitterness to the beer. More than an isolmerization chart will predict.

Saying that IBUs only come from isolmerized alpha acids is like saying high alpha hops are for 60 min additions and low alpha are for dry hopping. Ya, maybe a good starting point but keep experiencing and adapting to your experience

Was that from the Janish blog?

He had some really good stuff there.
http://scottjanish.com/zero-hot-side-hopped-neipa-hplc-testing-sensory-bitterness/

[Big Monk]

Here's a quote that indicates what I am feebly trying to articulate. "One obvious result from this experiment is that IBU values can not be directly substituted for isomerized α-acid values, especially at short steep times, high hopping rates, and sub-boiling temperatures.  This is because IBU values reflect not only isomerized α-acid values, but also contributions from oxidized α and βacids and polyphenols."

Um, soooo lab measured IBUs contain more than just isolmerized alpha acids. Like I said, whirlpool hops do bring bitterness to the beer. More than an isolmerization chart will predict.

IBUs by way of calculation are a sensory guidepost. I’m less concerned with absolute values and more concerned with how I can use the calculations to predict what tastes good to me.

[Robert]

I imagine the 2005 OSU study used fresh hops though. By oxidized alpha and beta, I dont think they mean stale.

Hops are also utilized differently now,  so there's equal but different opportunity to extract bitter substances other than iso-alpha.  In the day, increased solubility of beta offset decreases in alpha, then all the other stuff.  The whole BU concept needs reevaluation, which I presume they are working towards.

[klickitat jim]

Here's a quote that indicates what I am feebly trying to articulate. "One obvious result from this experiment is that IBU values can not be directly substituted for isomerized α-acid values, especially at short steep times, high hopping rates, and sub-boiling temperatures.  This is because IBU values reflect not only isomerized α-acid values, but also contributions from oxidized α and βacids and polyphenols."

Um, soooo lab measured IBUs contain more than just isolmerized alpha acids. Like I said, whirlpool hops do bring bitterness to the beer. More than an isolmerization chart will predict.

Saying that IBUs only come from isolmerized alpha acids is like saying high alpha hops are for 60 min additions and low alpha are for dry hopping. Ya, maybe a good starting point but keep experiencing and adapting to your experience

Was that from the Janish blog?

He had some really good stuff there.
http://scottjanish.com/zero-hot-side-hopped-neipa-hplc-testing-sensory-bitterness/

Alchemyoverlord? Can't find a name on it but it's obviously someone more sciency than me

[klickitat jim]

Here's a quote that indicates what I am feebly trying to articulate. "One obvious result from this experiment is that IBU values can not be directly substituted for isomerized α-acid values, especially at short steep times, high hopping rates, and sub-boiling temperatures.  This is because IBU values reflect not only isomerized α-acid values, but also contributions from oxidized α and βacids and polyphenols."

Um, soooo lab measured IBUs contain more than just isolmerized alpha acids. Like I said, whirlpool hops do bring bitterness to the beer. More than an isolmerization chart will predict.

IBUs by way of calculation are a sensory guidepost. I’m less concerned with absolute values and more concerned with how I can use the calculations to predict what tastes good to me.

Precisely!