Flame out hops and IBU's

[deeJay]

Hi, just interested in everyone's thoughts on flameout hops and their IBU contribution.
Watched a video from Nate, Tree house brewing doing and IPA recipe and he says flameout hops 0 ibu's
I have always included flameout hops in the ibu total.
What's your thoughts?
cheers.

 

[Minbari]

I am sure you get a couple ibu from it, just like dry hopping does. But it is not enough to worry about. Mostly for flavor and aroma

 

[dmtaylor]

It depends how long the hops are kept warm above a threshold of around 150-160 F (65-70 C). If you chill immediately then @Minbari is right and you'll get no discernible IBUs. If you keep the flameout hops in there to rest for 10 minutes or more, you will get noticeable IBUs. I have developed a downloadable IBU calculator for this here:

http://tinyurl.com/TaylorIBUCalculator

 

[Minbari]

It depends how long the hops are kept warm above a threshold of around 150-160 F (65-70 C). If you chill immediately then @Minbari is right and you'll get no discernible IBUs. If you keep the flameout hops in there to rest for 10 minutes or more, you will get noticeable IBUs. I have developed a downloadable IBU calculator for this here:

http://tinyurl.com/TaylorIBUCalculator

Nice, bookmarked

 

[Sandy Feet]

Aren't IBUs counted only in the boil? If it is after the boil, wouldn't it technically be zero? You will get some contribution from it, but it won't be calculated in IBUs.

 

[HighVoltageMan!]

It used to thought that alpha acid wouldn't isomerize below 180F, now we're not so sure. The alpha acids that contribute to bitterness are not soluble until they have isomerized and so no bitterness can come from them. This idea is old. Whirlpools as low 125F can contribute to bitterness. There may be more bitterness coming from the hops than just the isomerized alpha acids.

The problem lies not with the idea, but rather with the human that consumes the beer. Bitterness, as it turns out, is more complicated because it can't really be measured accurately with instruments, human perception is the ultimate measurement. Can a 0 minute addition add bitterness? Absolutely, it depends on the amount of hops, the alpha acid content and the time it takes to cool.

I brewed a Cold IPA recently with no boiled hops, only whirlpooled hops @ 165F. It's plenty bitter, to me it's 55-60 IBU.

 

[Minbari]

Aren't IBUs counted only in the boil? If it is after the boil, wouldn't it technically be zero? You will get some contribution from it, but it won't be calculated in IBUs.

No, you can add ibus in dry hop. Its just a measure of bitterness

 

[dmtaylor]

Aren't IBUs counted only in the boil? If it is after the boil, wouldn't it technically be zero? You will get some contribution from it, but it won't be calculated in IBUs.

Technically, IBUs by definition must be measured in a laboratory. Calculators can only provide a very rough ESTIMATE of the real IBUs that are measured by a lab. In truth, the flameout IBUs can be significant and it depends on how much are used, alpha acid content, and temperature. So technically, no, after the boil the IBU contribution is NOT zero. Probably never. Might only be 1 or 2 IBUs but not zero.

 

[Ward Chillington]

Yeah, IBUs are just a little subjective. Go find Experimental Brewing's episode with the Glen Tinseth interview. I think it's something like 'The IBU is a lie".

 

[Mark Farrall]

There's an older definition of an IBU as a unit of isomerised alpha acids. That's not what they test though. They test for any substance that hits a particular range where most of the bitter compounds occur. That is beta and alpha acids, isomerised or oxidised or in other states as well as other compounds. Some of these form more effectively with heat, others just by adding to the beer. So every time you add hops you're adding some level of bitterness.

And has been mentioned above, all the calculators we use are just very rough guesses. They have their problems, but they're better than nothing. I use them at the default settings and then adjust up or down based on tasting a batch. They'll always be slightly different with different ingredients and different process steps.

 

[Donoroto]

And for another opinion…

The chemical reaction that changes hop goop to bitterness takes place at hugh temperatures, like in boiling water. And down to 180 F or 160 F or whatever. But it isn’t like a light switch: it happens at lower temperatures too. Just not as quickly.

So even at 70 F there is some action, but not much.

All hops are highly similar but not identical.