IBU

[rivetcatcher]

Hello guys,

I have a question regarding the IBU. How do you determine the IBU of a beer?

If I was to take a ready made beer is there anyway to know what its IBU is? Is there a chart or rough guidelines to follow?

Thanks

[Manx Guy]

Hi,
Its quite a complex subject... heres my understanding of it:

IBU or EBU is an objective measurement of bittering - it is the amount of alpha acid in solution in a given volume of beer... So without lab equipment you can't 'measure' it...

There are calculations for working out the approximate IBU (bittering) of a beer you are going to make or are buying... The reason it is estimated is becasue the amount of bitterness extracted from the hops is dependant on several factors like the vigour and length of time the wort is boiled with the hops, the alpha acid content of the hops the age and condition (inc. processing of the hops before adding to the boil) and the gravity of the wort.

Quite a few brewers will give details of IBU's on thir website etc...

The thing is how bitter something is , can be quite subjective also... for example a beer with 40 IBU's can appear less bitter than one with 28 IBU's - becasue the 40 IBU beer may have plenty of residual maltyness (sweetness) from unfermented malt sugars still in the beer - despite the fact more hop bitterness was extracted.




Go to the hints & tips section of this site and follow calculator link - there are several calculators there that deal with bitterness....

Hope that helps!



Guy

[boingy]

IBU is typically calculated by the brewer, based on the quantity and Alpha Acid (AA) of the hops and also on the way the hops were used (longer boil = more bitterness extraction).

There is no easy way to measure the IBU of a finished beer. Arguably, someone with a decent palette and lots of experience could estimate the IBU by taste but it would not be very reliable. I daresay there is a laboratory method but I have no idea what that would be. On the upside, if you want to know about a particular commercial beer then name it and someone will probably have the IBU figure or will be able to estimate it.

There is a detailed discussion about IBU and stuff here:

www.howtobrew.com/section1/chapter5-5.html

In reality, most people either use brewing software to calculate the IBU or just use a recipe as it is presented.

[trucker5774]

Two good answers above.............http://www.hopandgrain.com/formulator.aspx If you have not seen this you can just fill it in to get the estimate. I know it doesn't help with what you asked about a finished beer, but that has been well explained.

[rivetcatcher]

Hi

Thanks for the responses and its definitely cleared it up a little more, it would be nice if somebody had a chart which plots approximate IBU ratings for different beers i.e an IPA should be between xIBU and xIBU etc, this would help me to know approximately what IBU I should be aiming to achieve for any given beer

Im sure Ive seen one somewhere but cannot for the life of me think where,

Thanks again for the help

[Aleman]

There is a publsihed method for measuring the IBU of beer/wort . . . but you do require access to a UV Capable spectophotometer . . . and they are not that cheap.

Brewlab do analyses for brewers . . . again not all that cheap, but it's up to you to determine if that is helpful . . .

[boingy]

There is a good set of guidelines here:

www.bjcp.org/2008styles/catdex.php

Note that it is USA-based so it gets quite a bit of slagging from European brewers who take offence at some of the categories but overall I find it a pretty good guide.

[Manx Guy]

The style guidelines are exactly that .. GUIDE lines...
Of course you can tweak the variables to make a beer within style to suit your individual tastes...

After all thats one of the reasons alot of us brew our own... to make OUR beer the ay WE like it!

There is a publsihed method for measuring the IBU of beer/wort . . . but you do require access to a UV Capable spectophotometer . . . and they are not that cheap.

Brewlab do analyses for brewers . . . again not all that cheap, but it's up to you to determine if that is helpful . . .

I didn't realise you were the master of understatement aleman...

Many years ago the lab i worked in replaced their UV spectophotometer - I recall it cost about the ten grand mark.....
Although I'm sure you can get them a bit cheaper....

I've no idea what they cost now as I no longer work in a lab (thankfully - wasn't really for me)



Guy

[rivetcatcher]

Hey Boingy, I agree thats quite a good guide and I will definitely use it as a guideline for my beers.

Cheers

[trucker5774]

Personal taste is the greatest factor for me. I have brewed to an IBU of 26 and thought it to be more bitter than other brews which were 35/40 IBU

[coatesg]

How bitter it tastes depends on a myriad of things - the start and finishing gravities (ie the balance), grist composition, ABV, hop variety, water (mineral content), pellets/flowers, in a bag or not, age of hops, the way your brewery works, phase of moon, etc etc.

As for the guidelines - treat them as such, and then adjust for how your system works and your own tastes (And even then - you'll be surprised how much your tastebuds can be misled - Pilsner Urquell is quoted as 40IBU, which is more bitter than most UK bitters, but few would say it tastes that way - and it's down to their very soft (low mineral) water).

[WishboneBrewery]

There is a publsihed method for measuring the IBU of beer/wort . . . but you do require access to a UV Capable spectophotometer . . . and they are not that cheap.
Brewlab do analyses for brewers . . . again not all that cheap, but it's up to you to determine if that is helpful . . .

I think I'd pay £21.95 to find out the Hop utilisation percentage of my Copper, just to give me some reassurance that was I am brewing is really hitting the mark.