Hop Utilization in whirlpool ( BITTER BATCH ! )

Remember at 175 F you have still 15 % of isomerization instead of 35% at boiling temp, so 20 min at 175 F those hops will give something around 13 additional IBUs.

 

I know I'm late to this discussion but I've had some recent experience with FF and a hopstand. Here was my recipe which was meant to be a West Coast Oktoberfest.

8.5# Vienna Malt
2# Malted Rye
2# Weyermann Carared

4oz. Falconer's Flight (I equally mix the original with the 7C's)
WLP #60
2oz. FF mix for dry hop

I started the hopstand at 190 degrees; put a 1/3 of total hopstand hops in at that time. Let that sit for 15 minutes, stirring every once in a while. After that 15 minutes the temp was down to 180. Put the next 1/3 in. Waited another 15 minutes (temp down to 170 or so) and put the last 1/3 in.
I'm drinking the finished beer right now. There's no other hop additions other than the stand in this recipe and from my taste I'd put the IBU's at about 55-60. The finished beer is about 6% abv. Of course the rye is adding a little spiciness as well.
This is the fifth hopstand beer I've done and all have had zero other hop additions and they all came out plenty bitter with tons of hop flavor/aroma. There is a little more hop astringency due to the amounts used and the fact that those hop oils aren't getting fully boiled out. The astringency may be what you're tasting here. Just think if you left a teabag steeping for way longer than advised. In the future you may try the hopstand schedule I use. The earlier additions at higher temperatures cancel the need for other boil additions and as the temp goes you down you kick in some new additions of flavor, so you're layering the hop utilization rather than taking what you get with one hopstand addition.
With regards to FF hops, yes they are very good but I've noticed in recipes I've made with them in the past that they do have a reasonable amount of bite to them. I've used Simcoe, Chinook, FF, Citra and Galaxy in hopstand recipes before. The recipes I've done that had a mixture of hop breeds came out better than the single hop hopstands. In fact, the recipe I put in this post would have been better had I replaced 1 ounce of FF with Amarillo. Also, should have backed down on the Vienna malt and replaced with Pilsner malt.

 

How are you getting these numbers? I'd like to understand how to better calculate my IBUs and I use many different whirlpool additions. Thanks.

 

Take a look here : http://www.mrmalty.com/late_hopping.php

 

I'd be interested as well...16-20% is generally what I hear for the >200F whirlpools that pro-brewers employ. The isomerization process is generally considered to shut-down around 175, hence the reason many homebrewers chill their wort to this level before adding their FO hops.

For calculation purposes only, what i've done for whirlpool additions is cut the whirlpool length in half and add that time to the boil length. This is strictly for hops adding just at or right after flameout and no chilling occurs besides natural cooling of the wort. So for a 30 minute whirlpool, I'd add 15 minutes onto my boil time when calculating IBUs. That is how i've set it up in my spreadsheet calculator...that equates out to about 10% utilization of alpha acids on a 30 minute whirlpool which is lower than what pros get, but that makes sense to me since our kettles are going to cool a lot faster than a pro brewer's tun.

 

It´s hard for me to say something about your above statement, I think it is not a bad method but I don´t know how reliable could it be.

 

FWIW, my brewing spreadsheet does IBU estimates for post-boil hop additions. It's modeled and extrapolated based on a paper by Mark G. Malowicki. Unfortunately, there's no practical (inexpensive) way to verify the results.

 

So, I'm late to the dick slapping party here, but I would like to share a recent experience. I brewed a hoppy saison this summer and its drinking nice, however it is suprisingly bitter. I used saaz and chinook in the boil to the tune of 20 ibus per beersmith. Anyway this brew sat and fermented for months (wlp670 american farmhouse) and the two weeks before bottling I decided to throw in an oz of chinook and an oz of citra. The beer turned out to be way more bitter than expected. It is as bitter as a snpa. Somehow I find it hard to believe that dryhopping doesn't add ibu's.

 

Here's the thread about features, etc. and a link to the download...
http://beeradvocate.com/community/threads/brewing-spreadsheet.95011/#post-1524696

 

<gulp> Just read this. Now my life has been scarred too.

 

I don't know how I missed this before, but thanks for this worksheet. Its pretty incredible.

I had a hopefully simple question about the whirlpool additions IBU calculation. Say I added 1 ounce of hops at flame out and let it cool over a half hour to 170. I then would add 1 ounce of hops for a half hour at which point the beer would be 150. Finally, I add 1 ounce of hops for another half hour at which point the beer is now down to 130. How would you suggest I enter that into your spreadsheet? What average temperature and time would I use for each step? Thanks.

 

Excellent question, and I don't have a perfect answer. It's worth noting that while chilling wort (or just letting it cool via ambient temp influence), the rate of temperature reduction slows down the lower you get, so during the period, your wort will spend much more time at the lower end than the higher. So for example, when going from 170F to 150F, you'd want to use an average somewhere below 160F.

I think there are a few folks on the forum that really know the thermodynamics of wort chilling inside out. Hopefully they will chime in.

 

using the Malowicki correlations, here are the correction factors:

170 F, 30 minutes - 14.7%
150 F, 30 minutes - 4.9%
130 F, 30 minutes - 1.5%

in other words, calculate the # of IBUs you would have gained by boiling for 30 minutes, then multiply by the correct % for each temperature to determine the actual IBUs added.

For instance, if you were adding 20 IBUs by boiling for 30 minutes, if you steeped at those temps for 30 minutes you'd actually add:

170 F ~ 3 IBU
150F ~ 1 IBU
130 F ~ 0.3 IBU

 

"Somehow I find it hard to believe that dryhopping doesn't add ibu's."

Sometimes I think we get too caught up in terms like IBUs...ever suck on a hop right off the bine? It is certainly bitter. Cheers

 

Chinook dry hops are a rough mutherf....

Dryhopping does not add ibu's. But ibu's aren't the be all / end all to perception of bitterness.

 

I get the impression from the description of the "bitterness" experienced that astringency is at play here - like sucking on a tea bag.

I wonder what temps the grains were steeped at if the bag was squeezed much.