Hops, times and bittering

[schmurf]

Can anyone give me an good explanation about how to deal with the hops that I...

• add in the boil; when do I remove these additions? At flameout? When chilling is completed?
• add at "flameout"; do I let these sit in the wort for just a minute? Or all the way down to pitching temp?
• add in hopstand/whirlpool; do I remove them from the wort after hopstand is completed? Or as above, all the way down to when chilling is completed?

If the boil hops and flameout hops are kept in the kettle all the way down to pitching temp, won't I have to add the chill time to the hop time? (I.e. 60 min + 20 min)? Most software gives 0 IBU for flameout hops, but some IBU:s for hopstand...if flameout hops are kept in the kettle down to pitching temp, don't they contribute to some IBU's?

Apologies if these questions have been answered 100 times before, but I can't find a good summarized answer with my poor google skills.

 

[sborz22]

For starters, you do not have to take out the boil hops at all. Many, if not most, homebrewers throw the hops straight into the kettle (other than post boil additions) therefore there is no way to simply remove them. After boiling stops the isomerization of hops may not completely stop but very drastically drops which is why the calculators only take into account boil additions and not post boil additions. You don't add in cooling time to your "boil" time on these calculators. So no, it would not be 60 plus 20.

The only time I have ever even considered guessing on hop IBU additions post boil was for an NEIPA where my whirlpool addition was put in around 180F with 3 oz of hops. Even then, as far as I know, there is not an accurate way to measure post boil IBU additions. I have seen people mention that adding more hops above 170F will add more IBU's but I cannot remember where I read that.

Lastly, back to the IBU itself, they are not all created equally. Where you will get bitterness from 60 min additions, you will get a much more flavorful hop presence with whirlpool additions which again, can still contribute to the IBU total but not actually add to the overall bitterness. Brew an NEIPA with all late hops additions and you will taste what I'm talking about! So don't fear that you will be making a bitter bomb by not calculating any marginal IBU additions from the whirlpool.

I am sure others will chime in as well!

 

[Hwk-I-St8]

I don't ever remove any hops. I have early boil, late boil, flame out and whirlpool additions. I also have the ability to chill to below 170 very quickly. If I had to do an ice bath chill or something that takes a long time, I'd probably treat it like a longer boil for IBU calcs.

Brewer's Friend and Brewsmith both add IBUs for flameout and whirlpool additions in their calculations. I have brewed NIEPAs with zero boil hops, but a ton of flameout and whirlpool hops that were not lacking in bitterness, so figuring zero IBUs for post boil additions when the quantities are large is probably a mistake.

The bottom line is that isomerization is occurring the entire time hops are in your wort and the temps are above 170.

If it takes a long time to chill, you could do your hop additions in a mesh bag and remove them when appropriate (like remove the 60 min addition at FO) if you were really worried about it. In general, the most important thing is consistency.

 

[ListerH]

From the bittering perspective, I always worked on the principle that the hop acids isomerize at temperatures above 175F and so it all depends on how quickly you are cooling that wort after flame out.

Doing a hopstand therefore will add some bitterness as the temperature stays above this mark for a short period after addition and the software I guess is reflecting this. It will also add a little bit of time for those hops added earlier in the boil.

I have tried to get more precise in terms of removing hops at flameout, but in order to be able to do this, I have used hop bags. The problem then is that I am never sure I get the same isomerization with a hop bag as just by dumping my hops in loose... so by trying to be too precise, I think you can tie yourself in knots! I do wonder how close my theoretical IBUs actually are to my actual IBUs.

 

[balrog]

I look at it as 3 distinct things, all of which act non-distinctly.
There are hop oils that isomerize to create bitternes, different ones add flavor, different ones add aroma. The last two vaporize in hot conditions, so you get no flavor/aroma adding them at 60m. Isomerization happens at 170-175+ and the degree of bitterness you get is temp/time dependent. I believe the IBU is about bitterness and does not speak to flavor. There is no IBUf or IBUa to find the amount (subjective?) of flavor/aroma garnered from (possibly hard to find) oil percentage values for given lots and ages of given hops.

So if you're warm, 170+, you'll get some bitterness and vaporize some flavor/aroma, but not as fast as adding hops 10m in 212°F. I have also read that the flavor additions post-boil, warm whirlpool, will give PERCEIVED bittering. It's all a mish-mash.

One man's viewpoint.

But to answer your specific question, throw em in, leave em in. I even dump em all the way into the fermenter after boil/chill. Please note: I do not make NEIPA styles so keep that in mind.

 

[ncbrewer]

This article deals with isomerization at lower temperatures: https://alchemyoverlord.wordpress.com/2016/03/06/an-analysis-of-sub-boiling-hop-utilization/
I use the factors in the article to adjust the estimated IBUs from late hop additions, and it seems to be accurate as far as my own taste buds are telling me. As far as the hops continuing to isomerize during wort cooling, the standard (e.g. Tinseth) formulas were developed empirically (with cooling at a normal rate), so a normal amount of cooling time should already be accounted for.

 

[schmurf]

Thanks guys, all great info, much appreciated

 

[BrewnWKopperKat]

won't I have to add the chill time to the hop time? (I.e. 60 min + 20 min)?

The IBU is a LIE! Kind of... is an interesting read.

Kettle Hop vs. Hop Stand | exBEERiment compares two recipes, on with just kettle hops and on with just a hop stand. In this exBEERiment, they let the 2nd wort sit for 20-ish minutes, then chilled rapidly. Compare this to the variety of chilling techniques in "The IBU is a LIE!". Basic Brewing Radio's "Hop Sampler" technique for SMaSH-ish hop sampling uses a similar approach - add all the hops at flame-out and let the wort sit for 30-ish minutes.

In the "Hop Queries" newsletter, "Bitterness has an altitude problem" (February 23, 2018) has a nice chart that shows the impacts of altitude (temperature lower boiling point) on hop utilization.

As @ncbrewer noted, 'Alchemy Overload' has a number of interesting articles related to post-boil hop additions. Scott Janish's blog (start here?) also is an interesting read. This - Topic: Best hopping - may also be helpful.

For a variety of reasons, homebrewing recipes tend to follow either a 'all kettle hops' or 'all whirlpool' hops approach. Using both kettle hops and whirlpool hops lengthens the brew day, but apparently doesn't offer any benefits over using just kettle hops or just whirlpool hops.

 

[Hwk-I-St8]

The IBU is a LIE! Kind of... is an interesting read.

Kettle Hop vs. Hop Stand | exBEERiment compares two recipes, on with just kettle hops and on with just a hop stand. In this exBEERiment, they let the 2nd wort sit for 20-ish minutes, then chilled rapidly. Compare this to the variety of chilling techniques in "The IBU is a LIE!". Basic Brewing Radio's "Hop Sampler" technique for SMaSH-ish hop sampling uses a similar approach - add all the hops at flame-out and let the wort sit for 30-ish minutes.

In the "Hop Queries" newsletter, "Bitterness has an altitude problem" (February 23, 2018) has a nice chart that shows the impacts of altitude (temperature lower boiling point) on hop utilization.

As @ncbrewer noted, 'Alchemy Overload' has a number of interesting articles related to post-boil hop additions. Scott Janish's blog (start here?) also is an interesting read. This - Topic: Best hopping - may also be helpful.

For a variety of reasons, homebrewing recipes tend to follow either a 'all kettle hops' or 'all whirlpool' hops approach. Using both kettle hops and whirlpool hops lengthens the brew day, but apparently doesn't offer any benefits over using just kettle hops or just whirlpool hops.

I have issues with many of these xbeeraments in that they frequently choose recipes that are likely to mute the results. For example, with this recipe, there's what...3 oz of hops total? In my recipes, I use close to double that in my whirlpool additions alone. There was another one where they were looking at the effects of some factor, but then chose a recipe where that factor wasn't likely to make much difference. I can't remember what it was, but I posted a comment about it a month or so ago.

So much popular brewing is pushing extremes: very high WP and dry hop additions, really high gravity stouts, etc that using generic mild beer recipes just aren't accurate representations of what many people are brewing these days (or at least not what I'm brewing and buying).

Also, adding hops at flameout and letting them sit for 30 minutes without chilling isn't all that different from boiling for 30 minutes from an isomerization perspective. I would expect much more difference if they added the hops at 170 degrees instead of flameout. I just don't see this experiment as very useful for my brewing.

 

[BrewnWKopperKat]

...adding hops at flameout and letting them sit for 30 minutes without chilling isn't all that different from boiling for 30 minutes from an isomerization perspective.

Which roughly matches the results of the brulosophy exBEERiment I mentioned.

I would expect much more difference if they added the hops at 170 degrees instead of flameout.

I would also.

Modify BBRs "Hop Sampler" process to bring the wort to a boil, chill to 180* F, add the hops, and hold the temperature for 20 minutes. For me, it's a very different beer than if I follow the regular "Hop Sampler" process.

I just don't see this experiment as very useful for my brewing.

I'm OK with that.

The intent of my earlier post was to build on what @ncbrewer wrote for either the OP or future readers. Often, when I do this, I get rewarded with additional links and ideas.

So much popular brewing is pushing extremes: very high WP and dry hop additions, really high gravity stouts, etc that using generic mild beer recipes just aren't accurate representations of what many people are brewing these days (or at least not what I'm brewing and buying).

And for many others, using generic mild beer recipes for experiments works well.