Flameout hops ibu's

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Jan 5, 2015
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Hi all, today I brewed my Hoppy new beer '24.

Decided to do a hop tea. Boiled some water and dumped 100g of Chinook(13% AA). Left it for 40 mins.

I did a quick search n Google about how many ibu's this would add but didn't come up with an exact answer.

I did come across a paper that shows hop utilisation is higher at lower gravity boils and that isomerisation stops at around 80c.

So I do have some bitterness but can't find an accurate calculator for how much.

Anywho, I usually do a 5 or 10 min (tops) boil and flame out for less. So if this works for me I've saved 10 mins of gas at the expense of a longer brew time.

Well I say longer brew time but my pitching temp was 20.4 bang in the middle so no cooling required. Mainly due to the fact Fv water temp from tap was 12c although the reduced water boil volume of 3.5 liters is less than the 6 litres I boil when I've added fermentables to the hop boil.

As I write this I realise time to boil has also been reduced.

I feel a spreadsheet coming on here.... Hop cost Vs energy cost. Is it better to pay more for hops and reduce cost of energy or not...

Must fight the urge and wait to see how the beer tastes 😜
Can't beat a good spreadsheet :laugh8:.

One thing you could try is constructing a recipe in whatever recipe software you use and just put in hops, water and time and it should guestimate the IBUs for you.
brewtarget and others don't really do flameout I assume they are using tinsel equations, anecdotal evidence ranges between 2 and 10% utilization.
I use this chart that Hazelwood put up from something he found.
I have used it for years and although I can not say it is 100% it seems to suit my purpose
Sorry it's not a good copy
IBU Chart.jpg
I use this chart that Hazelwood put up from something he found.
I have used it for years and although I can not say it is 100% it seems to suit my purpose
Sorry it's not a good copyView attachment 94585
Press the "print screen" button on your keyboard. It'll take a screenshot of your desktop and copy it to your clipboard. Then go to the forum and paste the picture into the post with ctrl-v
Here is my method. I've discussed this here in the past including conversions to SI units but have since tweaked the constants in the calculation so it would take some doing for me to create the SI version again. Anyway, here it is with American units (ounces and gallons).

@dad_of_jon and to anyone else interested... if you follow that link, but prefer to use SI units of grams instead of ounces, and liters instead of gallons, the calculation is exactly the same but you need to simply divide the result by 7.5. That is the conversion.

I'm still trying to get my head around using a 20 min boil and then decreasing bittering as a %age of what you have at flameout/whirlpool.

in reality I have 1 min at 100, 1 min at 99, 1 min at 98.... etc depending on heat loss from vessel.

I suspect if I could measure actual ibu's in beer by means of counting molecules responsible for bitterness then work backwards that would be better.
pragmatically I should sample the beer and see how it is. clearly if I want a really bitter beer I need bittering hops, what I'm trying to achieve is some bittering without losing the flavoring components of the hops.

My reality is I'm not a fan of boils, if I have to that it's as short as possible.

We will I believe each have our own preferences to the balance we want.

A cost of bitterness calculator would be cool. 🤔 less hops vs longer boil or more hops vs shorter boil.

If I was in my 20's I'd nail this with a formula or in my 30's a spreadsheet, however as i'm approaching a free bus pass in wales I use experience to get closer to the answer after 2 or 3 trial attempts. wink...

p.s. I designed a flexitime spreadsheet for my team (due to HR requirements) at a previous employer and it was so successful it was rolled out to the whole company. 20 years later it's still in use which is both embarrassing and amazing. ashock1 They've not found anything easier to use for timekeeping.

I suspect on my tombstone will be "What a spreadsheet" :laugh8:

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