Brewmate no chill box calculations

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Truman42

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I brewed a stout last night using an existing recipe I had in Brewmate but changed the grain bill and hops around to make an Oatmeal stout.

I didnt noice that the no chill box was ticked until I had finished brewing (Last time I brewed this I didnt own a chiller like I do now)

The hop additions was just 15 grams of Fuggles, 15 g of Northdown and 15 g of EKG at 60 mins and the IBUs came out at 36.5. When I unticked No chill it only dropped the IBUs to 35. Not much difference really.

How does Brewmate work out its Chill v No Chill hop calculations? I would have thought the diference would have been a lot more than just 1.5 IBUs?
 
don't know how it works but 60 minute additions will do very little as a no chill.

as a test change the 60 to 70 and see if they are just adding some additional time to the hops.
 
So is that because the hops have had all that time to add their bittering, vs if you were to wack in some hops at say 10 mins then no chill and they keep bittering while the wort cools down??
 
Don't know how it works either. But I do know know ticking and un ticking the box seems to show a profound difference in some cases.

I have a pretty lightly hopped Saison that jumps from 25 to 30 IBU's when you tick the no chill option. From memory this climbs according to the hopping rate, sometimes making the boxes turn yellow and letting you know you're 'out of style'.
So no chill makes you beer more bitter? There you go.
 
Truman you don't see much change in your recipe because after 60 min of boilling hops there is little change in the amount of bitterness extracted from them. When talking about late additions there can be a distinct change in IBU's, due to the software effectively increasing the extraction times of those additions.

I no chill and use the no chill checked. I adjust my recipes and bitterness levels according to this and also to my perceived bitterness.

Goid
 
As Goid said - its the later additions that change heaps.

Say you throw in a lot of hops at flameout.... Try putting in a 0 minute boil addition - 28 grams of something like Galaxy with a high AA% and then tick and untick the no-chill box.
You will see quite a big difference because when you add at 0 and then chill you add very little to no bitterness (just aroma), but if you no-chill then that extra time at high temp means it will be adding bitterness.
 
I **think** it just adds 15mins to the addition.
So a 60min addition to a 75min addition is stuff all difference in IBU. But if you have heaps of late hops it can make a huge difference.

Utilisation in say 1.040
0min to 15min = 0 to 0.125
but 60min to 75min = 0.252 to 0.264

So a 0 to 15min is 0.125 difference
but 60 to 75min is only 0.012 utilisation difference.

So approx 10% of the IBU value achieved with the bittering addition when compared to the late additions in a 1.040 wort.


edit: Just did a quick check, 1.060 is roughly 8.5%

QldKev
 
Dave70 said:
Don't know how it works either. But I do know know ticking and un ticking the box seems to show a profound difference in some cases.

I have a pretty lightly hopped Saison that jumps from 25 to 30 IBU's when you tick the no chill option. From memory this climbs according to the hopping rate, sometimes making the boxes turn yellow and letting you know you're 'out of style'.
Without knowing the recipes, I'd imagine that such a difference could also come down to the difference in boil gravities - with lower gravity beers seeing larger "spikes" than higher gravity ones for the same hop schedule.

Dave70 said:
So no chill makes you beer more bitter? There you go.
Chortled.

[EDIT: removed a bizarre cut and paste thing my browser likes to do.]
 
To directly answer your query Truman

You only had a 60min addition resulting in 36.5IBU
Assuming 1.040
From above 60min to 75min = 0.252 to 0.264
so 36.5 / .264 * .252 = 34.8409 IBU


even at 1.060
36.5 / .220 * .211 = 35.0068 IBU


So I agree with the numbers :D
 
Liam_snorkel said:
Yeah!

Like these guys. (actually looks more like pondering to me)


download_blog.jpg
 
Truman said:
I did..that post is almsot two years old and Brewmate has had a number of updates since then.
that thread is the most recent 'official' brewmate release thread.

the post is a year and a half old because that's when the no chill option was added to brewmate.

do you expect randyrob to start a thread every single time brewmate is updated?
 
Liam_snorkel said:
that thread is the most recent 'official' brewmate release thread.

the post is a year and a half old because that's when the no chill option was added to brewmate.

do you expect randyrob to start a thread every single time brewmate is updated?
Of course I bloody dont... What are you on to even suggest that???

But obviously its had a few upgrades since then and as the IBU diference between chill and no chill didnt seem to be very much I asked the question if there was other factors that brewmate considered when calculating the difference.

Perhaps the original way of adding 15 mins had changed as it was found not to be very accurate. Like things often do.

Those on here that actually do like to get involved in a discussion and help out did exactly that. Unlike you who seems only happy when your having a dig at people who ask a question that heaven forbid may have been asked sometime before in the past 30 years and in some slight way or form.

Do yourself a favour and block my posts as the stress will kill you. :D :ph34r:
 
:) Not stressed, sorry if I gave you the wrong impression. I just fetched the answer for your first question from the source, because everyone else's response was "I think it's this".

there have been a billion discussions on the effects of no chill on IBU, I assumed that this thread was specifically how brewmate calculated it. If you want an update, maybe send Randyrob a PM to check if it's changed in the past 18 months?
 
Liam_snorkel said:
:) Not stressed, sorry if I gave you the wrong impression. I just fetched the answer for your first question from the source, because everyone else's response was "I think it's this".

there have been a billion discussions on the effects of no chill on IBU, I assumed that this thread was specifically how brewmate calculated it. If you want an update, maybe send Randyrob a PM to check if it's changed in the past 18 months?
Well from what Kev said in his post it seems that it just adds 15 mins. I just expected a higher change in IBU for the 15 mins difference but as its been pointed out a 60 min addition isnt going to make much difference in IBUs when adding 15 mins, compared to a 15 or 10 min addition with no chill. So something Ive learnt. I thought lower additions were just for aroma and you needed at least 60 mins boil to get the bittering compounds from the hops.

Cheers
 
Truman said:
I thought lower additions were just for aroma and you needed at least 60 mins boil to get the bittering compounds from the hops.

Cheers
most brewing software AFAIK uses either the 'rager' or 'tinseth' method to calculate IBU (or an average of both) brewmate is no different. Have a play around with the formulas here: http://www.rooftopbrew.net/ibu.php and see what happens when you change the boil time. If you chuck enough hops of a high AA% in late in the boil you can get plenty of bitterness. Have a look at some 10min IPA threads.
cheers!
 
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