After 2 years of traditional mashing, I'm coming back to the BIAB fold.

I am wondering if the BIABacus provides any way to take into account the IBUs from a hopstand. For example, in a Blonde Ale recipe I am looking at, there is a 30-minute hopstand before chilling and pitching yeast. According to BeerSmith, the 60-minute boil hop addition contributes 17.9 IBU and the 30-minute hopstand contributes 6.9 IBUs, so for this recipe the hopstand contribution is significant (28% of the total IBUs).

Thanks!

(Hi, Pat! )

At this point, I believe neither Hop Stand or Whirlpool are reflected in IBUs. Been testing this out myself recently. It is possible Pat could have some to add.

BIABacus follows Tinseth's IBU estimation formula.

Scott, my 2 cents on this relates to how long at what temperature:

This is very interesting to me in terms of time and temperature effects on hop contribution to bitterness. Alpha Acids from hops isomerize during the boil to other compounds (bitter, in a good way) and then those compounds can change into not-so-good flavored compounds (bitter, in a bad way).

At the pH of the sweet liquor from the mash, the not-very-water-soluble humulones melt above 62 ºC and begin to isomerize (according to other sources) at temperatures above 80 ºC. The rate of change into good bitterness is tied to the temperature - higher T, faster rate. But don’t go for a pressure cooker, because the rate of degradation to bad flavors speeds up at higher T, too. The paper cited below looked at the rate of the isomerization reaction above 90 ºC. The rate below 90 ºC is so slow that it is boring.

What does any of this have to do with hopstand or whirlpool? Time & Temperature for recently added hops can impact the bitterness of the beer if only a little bit. Say you added hops for flavor at 30 min. If that (arbitrary) 30 minutes of boil time even starts to contribute measurable bitterness, then a 30 min hopstand at >90 ºC after flameout means that those hops are more bettering, less flavoring than you thought. If the wort temperature goes below 90 ºC, the rate is very slow, and if it goes below 80ºC, consider it negligible. What counts most is the total time at T >90 ºC and maybe >80 ºC, to a lesser degree. The term "hopstand" needs time and temperature attached to it. Sort of a recipe integrity thingy.

I am trying to keep track of my late hop additions relative to the future timepoint where the temperature goes below 90 ºC, then 80 ºC. There’s a lot of variables with my crude set-up, not to mention my brewing different recipes all the time.

For the more technical, see the abstract at http://pubs.acs.org/doi/abs/10.1021/jf0481296 (paywall to the full article) The last sentence there concurs with the idea that hops should not be boiled for longer than 60 min. FWH is a different discussion.

Hi ShorePoints,

Original Poster for this thread (smyrnaquince) must be channeling my thoughts , as I have been in the same sort of thought pattern as of late. Appears you have too... His post seems to coincide with some posts I've written, and thoughts I've had recently as well.

I did a test brew on Saturday, comparing results on different chill times. All were chilled with immersion chiller fairly quickly. After Flame Out, I transferred 2 gallons into my older, smaller brew kettle (should have measured...was planning on 3 gallons). The smaller kettle was then pretty much immediately chilled. So call it FO+4 minutes I officially started that chill, but the water was running throughout so temperature was likely below 190F degrees almost immediately. At FO+14 minutes I moved the immersion chiller to the big pot with around 6.5 gallons in it. Stopped chilling process @ FO+24 minutes. I want to see what impact this hop stand had on hops, vs. immediate chilling which I've almost always done.

Another interesting test would be to do a quick chill - run water for only 10 seconds or so to drop it to the 190F degree range...then maybe have a hop stand there for 10 minutes, and then chill entirely. If we have some late hop additions like at 0 min, wonder what the difference would end up being...? Perhaps should run it down to 180F degrees instead and do the hop stand there. Would have to somehow figure a way to do a side-by-side to know for sure. If you've done this, let me know how it turned out.

EDIT - your link needs some sort of membership for more than a couple paragraphs. Pretty thick stuff there...appeared to be.

Scott

smyrnaquince wrote: ↑

8 years ago

(Hi, Pat! )

Hi to you Dave! Nice to see you back

Sorry Dave, I thought I had actually already written here already. Must have pressed a wrong button or something

[NOTE: For those of you who don't know, Dave helped out behind the scenes on BIABacus stuff in the past. I always remember Dave, not because he sometimes found an obvious flaw (we all did that) but because several times he wrote something I initially thought was wrong but, after consideration, found it was something that we/I had not considered or just got the wording wrong.]

Okay, on to the subject matter....

smyrnaquince wrote: ↑

8 years ago

After 2 years of traditional mashing, I'm coming back to the BIAB fold.
I am wondering if the BIABacus provides any way to take into account the IBUs from a hopstand. For example, in a Blonde Ale recipe I am looking at, there is a 30-minute hopstand before chilling and pitching yeast. According to BeerSmith, the 60-minute boil hop addition contributes 17.9 IBU and the 30-minute hopstand contributes 6.9 IBUs, so for this recipe the hopstand contribution is significant (28% of the total IBUs)....

I think the reason why I thought I had already replied here was that I wrote two comprehensive posts on this very subject very recently.

Read this and the link within it.

Does that make sense Dave?

PP

Dave.....A 30 minute hopstand will impart aromas plus very few IBUs .Just like adding hops at flameout. I will try to find the article I read on adding hops at these time and post the link. If you are looking for IBUs , try adding around 15 minutes. At that time you will get 50% flavor & 50% aroma utilization .
J