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Confused about IBUs


Cassius

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For my 5th extract brew I want to try and make a proper pale ale (having used the Australian Pale ale extract a couple of times by now without any hop boil for added bitterness). I've been looking through the recipes on the diybeer site and something isn't adding up, almost certainly on my end.

The Coopers Session Ale seems to offer what I'm after but when I put the ingredients in the Beer Designer spreadsheet, I'm getting 19.3 IBU and not the 27 they claim on the recipe page. As I understand it, neither the hop steep or dry hopping in this recipe add bitterness. So what is the cause of the discrepancy? I'm aiming for a BU:GU of around 65 to 75. At 27 IBU the BU:GU is 0.68, while at 19.3 IBU it's way lower than I want, at 0.47.

While I'm here, does anyone have any recommendations for a sessionable pale ale recipe with good hop flavour and aroma. I'm happy to do a hop boil but it's not a necessity. I drink lots of craft pale ales and like basically all of them, then instantly forget their names. My go-to mass-produced one is probably Kosciuszko. I would prefer to not do anything with grains as I'm still learning the easy parts of the kit process.

Cheers in advance.

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44 minutes ago, Cassius said:

For my 5th extract brew I want to try and make a proper pale ale (having used the Australian Pale ale extract a couple of times by now without any hop boil for added bitterness). I've been looking through the recipes on the diybeer site and something isn't adding up, almost certainly on my end.

The Coopers Session Ale seems to offer what I'm after but when I put the ingredients in the Beer Designer spreadsheet, I'm getting 19.3 IBU and not the 27 they claim on the recipe page. As I understand it, neither the hop steep or dry hopping in this recipe add bitterness. So what is the cause of the discrepancy? I'm aiming for a BU:GU of around 65 to 75. At 27 IBU the BU:GU is 0.68, while at 19.3 IBU it's way lower than I want, at 0.47.

While I'm here, does anyone have any recommendations for a sessionable pale ale recipe with good hop flavour and aroma. I'm happy to do a hop boil but it's not a necessity. I drink lots of craft pale ales and like basically all of them, then instantly forget their names. My go-to mass-produced one is probably Kosciuszko. I would prefer to not do anything with grains as I'm still learning the easy parts of the kit process.

Cheers in advance.

Hi mate.

The hop tea that is in the recipe will add some bitterness to the brew. When you add hops to any wort or water above around 80C, the alpha acids isomerize which causes them to taste bitter. The exact bitterness of hop stands/teas cannot be worked out on the IanH spreadsheet unfortunately. It would not be a huge amount though, maybe <5IBU's.

However, you have made me look into things a little more - and on the Coopers website it states that product bitterness is calculated by obtaining the concentrated bitterness of the kit (the Australian Pale Ale is rated at 340IBU), then multiplying it by 1.7 then dividing by the volume (in L) of the brew.
In your example, this would be: 340 X 1.7 / 22 = 26IBU. This can be seen below:

image.thumb.png.33c9ef55448b868491335419b3d7b0e0.png

image.thumb.png.1017296d9d9aa8503435ca9ccdaaa3cd.png

So after working this out I have checked how the IanH spreadsheet determines bitterness and it is different to how Coopers state to calculate it. See below.

image.png.a0575ca3d3688425085aac4c563ac93b.png

 

The IanH spreadsheet is only multiplying by 1.25. If you fix the formula to how Coopers state to work out their IBU's, your recipe results in this:

image.thumb.png.4e45817f9a69bb219f71bc6938891fa4.png

 

Now the recipe online states 27IBU, so therefore Coopers have probably concluded the small hop tea has added another 1IBU to the brew and boom there we have 27IBU.

So according to how Coopers calculate bitterness in their kits, the IanH spreadsheet is calculating the Coopers Kits bitterness incorrect. Interesting.......

Mitch.

Edited by MitchellScott
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3 minutes ago, MitchellScott said:

Hi mate.

The hop tea that is in the recipe will add some bitterness to the brew. When you add hops to any wort or water above around 80C, the alpha acids isomerize which causes them to taste bitter. The exact bitterness of hop stands/teas cannot be worked out on the IanH spreadsheet unfortunately. It would not be a huge amount though, maybe <5IBU's.

However, you have made me look into things a little more - and on the Coopers website it states that product bitterness is calculated by obtaining the concentrated bitterness of the kit (the Australian Pale Ale is rated at 340IBU), then multiplying it by 1.7 then dividing by the volume (in L) of the brew.
In your example, this would be: 340 X 1.7 / 22 = 26IBU.

So after working this out I have checked how the IanH spreadsheet determines bitterness and it is different to how Coopers state to calculate it. See below

The IanH spreadsheet is only multiplying by 1.25. If you fix the formula to how Coopers state to work out their IBU's, your recipe results in this:

Now the recipe online states 27IBU, so therefore Coopers have probably concluded the small hop tea has added another 1IBU to the brew and boom there we have 27IBU.

So according to how Coopers calculate bitterness in their kits, the IanH spreadsheet is calculating the Coopers Kits bitterness incorrect. Interesting.......

Mitch.

Wow, very interesting. Thanks for looking into that for me but now I don't know what to believe. What makes me even more confused is that the first beer I made was just the standard Coopers APA recipe (as a baseline) and it's not bitter at all, to my taste. This leads me to think that maybe I should follow the spreadsheet IBUs, if only to achieve the level of bitterness I'm after.

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2 minutes ago, Cassius said:

Wow, very interesting. Thanks for looking into that for me but now I don't know what to believe. What makes me even more confused is that the first beer I made was just the standard Coopers APA recipe (as a baseline) and it's not bitter at all, to my taste. This leads me to think that maybe I should follow the spreadsheet IBUs, if only to achieve the level of bitterness I'm after.

I would personally be going by Coopers calculations. After all, they are the ones who are making the product so you would assume their calculations are correct.

25-26IBU is not a bitter beer. Its only marginally more bitter then your megaswill beers (Great Northern, Super Dry etc). Hence why a lot of recipes that use this kit have small hop boils in them to up the bitterness a little.

Cheers.

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5 minutes ago, MitchellScott said:

I would personally be going by Coopers calculations. After all, they are the ones who are making the product so you would assume their calculations are correct.

25-26IBU is not a bitter beer. Its only marginally more bitter then your megaswill beers (Great Northern, Super Dry etc). Hence why a lot of recipes that use this kit have small hop boils in them to up the bitterness a little.

Cheers.

Fair enough. I'm just basing it on an AHB thread I found that says to focus on bitterness to gravity ratio, with 0.65 being an "easy drinking pale ale" and 0.75 being an APA. With the Session Ale recipe, assuming 27 IBU and OG of 1.041, gives a BU:GU of 0.66, which is right where I want to be.

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5 hours ago, Ben 10 said:

@PB2 or @Coopers DIY Beer Team can confirm but I'm guessing they chemically test the IBU? I know they test the alcohol content rather than relying on a formula.
Coopers numbers will be more accurate than a spreadsheet.

Cheers Ben. I've updated my numbers in the spread sheet to reflect the Coopers calculation.

My plan is to try this Session Ale but I'm wondering if there is a dry yeast alternative to the Coopers Commercial Yeast. I've been using US-05 for a few of my brews so far but have read you may not get true pale ale flavour from this (I've used it for essential "Blonde Ales" so far). Would Nottingham or something else be a better option?

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With brewing, there's a big element of trial and error to begin with. Personally when starting, I wouldn't trying to hit numbers to get what you're after, until you've brewed enough beers to know by taste exactly what that is.

I still have no idea what IBUs I 'like' and what is too bitter. Different beers taste different and in some, the higher IBU are fine if well balanced with other ingredients. Likewise, low IBUs in my summer ales are fine because I want a lightly hopped slammer. I brews kits I think I'll like with hops that suit the style, or I've had good results with.

Likewise yeasts, I've brewed pales with S04, SO5, Nottingham and kit yeasts. They all work. There is no one true pale ale flavour - the style has got too massive and diverse to define it as one thing. Brew the beer you like, not what a style guideline says is correct or true to style. To brew beers you like, you get to know your ingredients and how to use them.

Edited by Lab Rat
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The spreadsheet calculation is based on the kit volume rather than weight like the Coopers calculation. That's why they're different. 

IBU is more of a guide than anything. The same figure can taste quite different depending on the other ingredients. 

Style guides don't have to be strictly adhered to but they are useful for brewing different styles when you aren't quite sure what should go into it. I still use them now when constructing recipes, better than just throwing a heap of random shit together and hoping for the best. 

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37 minutes ago, Otto Von Blotto said:

I still use them now when constructing recipes, better than just throwing a heap of random shit together and hoping for the best. 

I wasn't advocating that, but Coopers recipes are a good place to start. A year later, I'm still there, trying different styles or trying to make previous brews I liked work better.

I've found Pales are easy and reliable to make - this is where you can go off and do your own thing with a pale can & liq / dry malt or BE boxes, and whatever pale ale friendly hops you feel like. There enough of those to keep anyone busy for a while...

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10 hours ago, Lab Rat said:

With brewing, there's a big element of trial and error to begin with. Personally when starting, I wouldn't trying to hit numbers to get what you're after, until you've brewed enough beers to know by taste exactly what that is.

I still have no idea what IBUs I 'like' and what is too bitter. Different beers taste different and in some, the higher IBU are fine if well balanced with other ingredients. Likewise, low IBUs in my summer ales are fine because I want a lightly hopped slammer. I brews kits I think I'll like with hops that suit the style, or I've had good results with.

Likewise yeasts, I've brewed pales with S04, SO5, Nottingham and kit yeasts. They all work. There is no one true pale ale flavour - the style has got too massive and diverse to define it as one thing. Brew the beer you like, not what a style guideline says is correct or true to style. To brew beers you like, you get to know your ingredients and how to use them.

Yeah that's fair enough. I think it's because I'm an engineer and love spreadsheets; I'm absolutely fascinated by this IanH spreadsheet. I'm also recording everything I'm doing so I can go back and look at what I liked and didn't like then try to improve on it. I think part of the issue is that most of the information seems to be in forums, which is great, but it also means there's so much information that's based on opinion. I'm almost spoilt.

Apart from the German styles, my main beer is definitely Pale Ale. So I think I'll do as you say and just use the same Coopers APA kit and light malt then try changing up the yeast and hop combinations to figure out what I like. I put down a variation of the Fruit Salad Ale last night and as soon as I opened the bag of Galaxy hops it just smelt exactly like what I like to taste in my pale ales, so I think that's a good place to start.

Thanks heaps for your time.

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10 hours ago, Otto Von Blotto said:

The spreadsheet calculation is based on the kit volume rather than weight like the Coopers calculation. That's why they're different. 

IBU is more of a guide than anything. The same figure can taste quite different depending on the other ingredients. 

Style guides don't have to be strictly adhered to but they are useful for brewing different styles when you aren't quite sure what should go into it. I still use them now when constructing recipes, better than just throwing a heap of random shit together and hoping for the best. 

I think part of the issue is that I know what beers I like, but I'm not sure exactly what it is that makes me like them. I rarely drink a pale ale I don't like but if I have an IPA I usually enjoy the first schooner and then want something a bit more easy-drinking. The other thing is that I'm basically trying to go on a homebrew journey that starts with the most basic recipe (APA can and brew enhancer 2), moves onto some dry hopping, some hop steeping and eventually I'll move onto AG once I feel I have all of the other elements down. So I'd like to try some hop boils to increase bitterness, even if it's not strictly necessary to make an easy-drinking pale ale.

Cheers.

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1 hour ago, Ben 10 said:

Not sure.

I like MJ's Liberty Bell as a great all rounder. I'm not a big user of US Ale Yeasts like US05, MJ's M44)

It's funny you say that. The one time I used US-05 the krausen took over 2 weeks to drop out, whereas I used the MJ-20 in a hefeweizen and it went off like a bomb and was cleared up by about 5 days (the MJ-20 was at higher temp, which could have been a factor). I think I'll start with the US-05 for this Session Ale and then try the Liberty Bell for comparison.

Is there a reason you don't like US-05?

Cheers.

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18 minutes ago, Cassius said:

It's funny you say that. The one time I used US-05 the krausen took over 2 weeks to drop out, whereas I used the MJ-20 in a hefeweizen and it went off like a bomb and was cleared up by about 5 days (the MJ-20 was at higher temp, which could have been a factor). I think I'll start with the US-05 for this Session Ale and then try the Liberty Bell for comparison.

Is there a reason you don't like US-05?

Cheers.

Once again is it all opinion but I like US-05 in my hop heavy beers as it doesn't really effect the flavour much, so it allows the hops/malt to stand out whereas some other yeasts will ferment out with a different/yeasty flavour that can hide some of the hop flavours in a hopped up beer.
The Krausen does certainly like to hang around though. I find that adding my dry hop sock with dry hops tends to get rid of it pretty quick... Once you put a small hole in it the rest falls away fast. Cold crashing will obviously help too.

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4 minutes ago, MitchellScott said:

Once again is it all opinion but I like US-05 in my hop heavy beers as it doesn't really effect the flavour much, so it allows the hops/malt to stand out whereas some other yeasts will ferment out with a different/yeasty flavour that can hide some of the hop flavours in a hopped up beer.
The Krausen does certainly like to hang around though. I find that adding my dry hop sock with dry hops tends to get rid of it pretty quick... Once you put a small hole in it the rest falls away fast. Cold crashing will obviously help too.

Ah perfect. This Fruit Salad Ale is likely the last time I'll use US-05 without dry hopping so from now on I'll give it a good hop depth charge and see if that hurries it along. Cheers.

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3 minutes ago, Otto Von Blotto said:

That's exactly why I like it in pale ales, lets the hops and malt dominate. It does have a tendency for krausens that take forever to drop, but I find cold crashing sorts that out pretty easily.

I don't have the means to cold crash just yet but I'll definitely keep that in mind. Would like to move to a fridge and inkbird setup like most people around here seem to be running. I'll eventually move to kegging once I have some spare cash as I'd like to have some taps to go with the bar in my house. Cheers.

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Hey @Ben 10

You are spot on, IBU’s are calculated as described in the FAQs:

IBU x Weight / Volume = IBU. So in this case it is: 340 x 1.7 / 22 = 26 IBU.

There was some additional IBU’s contributed by the steep addition, but there are also some IBU losses during fermentation.

Unfortunately there is no perfect IBU calculator and they should only be used as a guide.

Happy brewing 🍻

Coopers DIY Beer Team

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10 hours ago, Coopers DIY Beer Team said:

Unfortunately there is no perfect IBU calculator and they should only be used as a guide.

Truer words were never spoken. 

One thing that will help is keeping notes on what you think of the recipe after you have begun to drink it, as your memory of it will fade fast.

1+ what Kelsey said about how other ingredients can change the flavour of the exact same hop schedule: a different percentage of the same crystal malt, a different colour crystal malt of the same percentage, or the even the same colour crystal made by a different maltster (ie English vs German vs Belgian vs American vs Australian).

Cheers,

Christina.

Edited by ChristinaS1
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