Adding all the IBUs at Flame Out or Later

[terrym]

I am not an AG brewer but do make up extract brews from time to time and use the Brewers Friend Calculator to help me, particularly when calculating bitterness i.e. IBUs. My understanding from using this has been that there is negligible bitterness added to the wort after flame out, provided the wort is allowed to steadily cool. And this basic understanding I have seen echoed on here from time to time.
However there have been two recent threads on here concerning NEIPAs and what I seem understand from others is that they get their bitterness from adding lots of hops at flame out or later, as well the significant hop flavours and aroma for which this class of beer is recognised
And since my understanding from a few references is that NEIPAs have a medium bitterness and a couple of home brew recipes indicate 40-50ish IBUs, the contribution of the post flame out hops is not insignificant
So my question to those who will know about these things more than I do is, how do brewers calculate the IBUs in NEIPA beer when hops appear to added at or later than flame out, or is it some sort of dark art?
Or am I missing the point somewhere?

 

[BeerCat]

Interesting question. I just made a NEIPA and added all the hops at exactly 75c. According to brewers friend that gave me nearly 30 IBU and it did have some bitterness so i would say probably not far off. As i didn't boil i used the mash setting in brewersfriend. 150g is not a lot to add but i used high AA hops. I never worry about a beer not being bitter enough anymore as you can either boil some hops in water or use hop oil.

 

[Hoppyland]

Yep, an interesting question. Not one I can fully answer - but, I always no-chill, and my beer cools very slowly overnight, so I can offer my experience.
Unless I'm in a huge hurry, all of my beers are AG. Firstly, I rely on the boil for bittering. A typical bitter beer recipe of mine would require 15g of Warrior boiled for 60mins. Then, I will add steeping hops once the boil is finished, and leave these hops to steep overnight. Now, I do believe (from experience, not just theory) that these can add significant bitterness, although I've never tried to measure my cooling profile or estimate what the increased bitterness actually is. But, to reduce this uncertainty to a minimum then I try to add very low-alpha hops as the late addition. No prob with English bitters, Fuggle and Goldings aren't likely to create too much bitterness. Less obvious with some of the newer hops, where even the aroma varieties can also be very high alpha. So, I tend to use low-alpha hops for late addition (for IPAs such as Wa'iti, Ahtanum, Riwaka, Lemon Drop) and then save the "big hitters" for dry-hop.
For me, no problem. But then, I mainly brew only my own recipes - or variations on them - so I know what to expect.

 

[dan125]

My understanding of it is that the rate of isomerisation slows down as the temp drops from 100C but still happens at lower temps after flame out.
The latest version of Beersmith calculates/estimates the IBUs from whirlpool/steeping hops at any given temp, but before I got that I was just using trial & error pretty much.
I also think dry hops can add to the perceived bitterness (anyone else tasted a hop pellet?).
The added IBUs from post boil hops is probably fairly negligable when using small amount of low AA hops, but not when using silly amounts of high AA hops in a NEIPA.
Personally when brewing a NEIPA I don't aim for a particular amount of IBUS like I would with a AIPA - I just try to keep them as low as possible.

 

[dan125]

The Basic Brewing Radio episode from Nov 1st is an interesting listen on the topic:

http://www.basicbrewing.com/index.php?page=radio

 

[MyQul]

Going on (limited) experience even hop teas seem to add bitterness. I normally hop my bitters to 0.7 (IBU dividedOG. Known as the bitterness ratio)* but my last bitter I decided to add a hop tea (25g of challenger steeped for 30mins at about 75C-80C). The boil hops I did to my normal 0.7 thinking the hop tea wouldnt add any IBU's. But the final beer definately tasted more bitter than usual. More like 0.8-0.85

*If anyone isnt aware about what I'm going on about with this, dividing the IBU's by the OG is a very useful calculation when making you own recipes or adapting existing ones as it gives you a number (bitterness ratio) to aim for when making a particular style. The graph below tells you what number to aim for with any one particular style

http://www.madalchemist.com/chart_bitterness_ratio.html

 

[braziliain]

This is interesting.

I noticed recently while making the Gammaray recipe from the Craft Beer for the People book that software doesnt seem to handle this too well.

The recipe states that IBU is around 45, but after entering the hop schedule into both Brewfather and Beersmith, both apps agreed that the IBU should be around 17. The majority of the hops in the schedule are added in a hopstand at 80C.

The beer is still fermenting, so haven't tried it yet.

 

[divrack]

Yes it's really only a guesstimate as proscess will differ, however a good start point is to use the brewers friend or beersmith app and the whirlpool calculator.
Bear in mind that the calculator has only a set temp field to work out the isomerisation, which is don't think allows for cooling in its calculation. So for a flameout addition you might want to enter a temp somewhere in the middle of the temperature range or devide it into two additions at a higher and lower temp for half the total stand time.
Also worth note is that any late boil hops will also contribute some extra bitterness in the stand unless removed which would be a waste.

Really the variables are such that you are better just learning from previous experience and adjusting.

Also many of the best neipas will add some boil additions, really beer is beer and you can do what you want. You can make a great neipa breaking every so called rule of neipa dogma.
I feel that active fermentation dry hopping is important, but that's just kind of my own arbitrary definition of what an neipa is.
Again beer is beer.

 

[stz]

Isomerisation continues down to 79C. Hop stands at high temperatures have the potential to contribute significant bitterness depending on hop AA%, amount, time and temperature. So to answer .. negligible bitterness? Negligible, but not insignificant in a more traditional brew, definitely should be considered in something like a NEIPA. Calculate or not? Well this is a can of worms.

Short of laboratory analysis on finished beer all brewhouse IBU calculations and such when formulating recipes NEED to be accepted for what they are .. a fairly subjective measure of 'brewery bitterness'. As long as you work them out the same way each time and do the same sorts of things on brew day and your taste buds are the final assessor they are a useful way to allow you to formulate and adjust recipes. It doesn't matter if you calculate everything out at 10 or 100 IBU's as long as you know what you need to do to make that number half as much or twice as much and it works and your assessment of the final beer feeds back into it.

So that said does it matter? Is it any more useful than measuring with handfuls or similar? My point is don't get too caught up on it, but do think about how hops, even unboiled can contribute a bitter taste even if that bitterness isn't from isomerised alpha acids (theoretical IBU's aren't the be all and end all) and how proven techniques can be adapted (hop stands, transfer time, low temperature hop stands, whirlpools, hop backs etc) to get you where you want on your equipment.

Calculating theoretical IBU's is the usual AAU x U x 10 / V for me, except any hop stand and transfer time. The calculation doesn't work because there is no 'boil' time to get the utilisation for. For this I use 25% of the standard utilisation for the whole duration of both. I will stand up and say this isn't scientific, but it gets me where I need to be as I adjust from the same point each time. There is totally utilisation from hops in contact with 96-98C wort throughout the duration.

For beers where these numbers get slightly terrifying I will do a whirlpool and chill the wort down. I used to play around with different times and temperatures, but have pretty much settled on stirring them in and then starting the whirlpool and chilling immediately as it takes typically less than 30m to completely chill the wort, it is certainly 60C or less by 10-15m. For these I use 5% of the standard utilisation for the duration.

Another method I'll use as a compromise between the two is stirring them in at knock out, but immediately starting the transfer so they have only a short contact time. I'm less fond of this as I use leaf in the copper and like to allow some settling for filtration and I can always use the previous method, with some boil hops to bring up the bittering.

Anyway, that is what I do. I do quite a few things a bit differently sometimes, but usually have a reason for them. Rarely do 60m mashes, usually mash time is based on diastatic power and mash temperature depending on goals. Rarely do 60m boils, usually boil time is based on DMS potential of the grist and evaporation depending on goals. NEIPA's are usually no boil hops, 30-40m boil depending on nitrogen content of the malt, hops go in, whirlpool starts, chilling goes on, divert to FV once the copper temperature drops below 60C. Mash is usually 64-65C, simple brew day.

Body is build with a little dextrine malt, wheat, oats, whatever you like to use for protein though less than you'd think due to proteins and lipids will rapidly oxidise in the presence of oxygen, rarely bother with copper fining though yeast influences that choice. Sweetness is water treatment, limited adjuncts and hop choices. Final gravity is more a product of yeast selection, yeast is selected for esters, fermentation speed and attenuation, flocculation not so much. The real work is in the dry hopping and packaging.

It also depends on what school of thought you come from regarding these beers. Should they be a healthy 5.5-6.5% abv or 4%? Should they be hazy or cloudy? Bit of yeast or absolutely snided? Decent orange colour or pale yellow?

 

[Pavros]

@terrym
Thanks for starting this thread. I contributed to one of the other threads but want to hear from the people with experience of making these beers too. Some interesting posts so far!

 

[BeerCat]

The beer i made last week with hops steeped at exactly 75c definitely has some bitterness. Hard to say how much but certainly enough.