Hopping to IBU's

[deadlydes]

Right i have seen in most your your recipes the the IBU is used.

what is it and knowing the AA of my hops how do i know how many IBU's i am adding?

i have read the bit in DL's BBoB and the AAU seems very old since its based on onces etc. is this unit still used?

thanks in advance

[Andy]

Hi Des!

IBU's are International Bittering Units - it's an attempt to provide a measure of bitterness!

There's a handy online calculator here which allows you to work out your IBU total
from amount/type of hops used and the time boiled.

http://realbeer.com/hops/bcalc_js.html

[deadlydes]

Thanks andy.
so is the IBU still based on ounces?
also i know this may be a too broad question to answer but how many IBU's does a beer need? as i said i know this is probably to broad but what about rough guides/max and min, for diffrent types of beers.

[Andy]

That calculator only has ounces as it's 'murcan Just convert from grams to oz first..

Google has a good conversion tool e.g.

http://www.google.co.uk/search?q=30+grams+in+oz

And you can get an idea of IBU's for beer styles from the beer http://bb.mafmods.com/picatures/beeriodictable.gif DaaB posted the other day!

[deadlydes]

Thanks again
i went to click that periodic table link the other day and it didnt work. and it still doesnt work now! can anyone get it to work? the link links to http://bb.mafmods.com/picatures/beeriodictable.gif

have tried googling it but just get really small unreadable ones.

or if someone could email me a copy desdeadly (at) hotmail (dot) com
cheers

[Andy]

Try right clicking on the link above and "Save Link As.." to your desktop. This will save the image to your PC desktop. You *should* then be able to double click on the file and view it in the windows image viewer.

I assume you're on Windows ? What version ?

[Road Runner]

So what's the difference between IBU's & EBU's? The recipe book I mainly use has bittering units quoted in EBU's (European Bittering Units).

Des. The understanding I have of bittering units, is that hops obviously have different Alpha Acid Levels. These alpha acids vary year to year on the hop harvest. Alpha acids determine the level of bitterness of a beer. A beer will be brewed to a certain bitterness depending on the beers recipe, say 24 EBU's, using hops of 4% Alpha Acid.

If you were to use hops of a higher alpha acid, you would need to reduce your hop levels during the boil to achieve the same level of bitterness as your recipe requires. You need to multiply the original hop weight by the original hop alpha acid. Then divide it by the new hops, or replacement hops, alpha acid.

This is the calculation I use for the required EBU level.

weight of original hop X alpha acid of original hop
_________________________________________ = new hop weight for boil

substitute hops alpha acid or new acid content


Example: You want to brew a beer of 24 EBU and the original recipe used 75 grams of hops of 4% alpha acid. Your hops have an alpha acid of 5.1%. Using the above calculation, it works out thus:

75 x 4
_____ = 58.8 gram, new hop weight for boil

5.1

I have recently been told, that the major brewerys are now demanding higher alpha acid hops from the hop growers, so they can reduce the hop content during their boils, thus saving the brewerys a lot of money on hops. I have also noticed that all the hops I buy, have a higher alpha acid than the recipes in the books I use, probably because of this reason.

I hope this helps.

RR.

[Andy]

OK, I've hosted the beeriodic table http://www.knownentity.com/misc/beeriod ... maller.jpg

[Jim]

That link doesn't work for me, Andy.

As far as I know, IBUs and EBUs are the same unit.

[Andy]

Link thing amended. The image is huuuuge and Internet Explorer can't cope with it!

I run Firefox which views it fine so was a bit baffled as to why you all couldn't see the thing!

I've shrunk the image a bit, means you can't read some of the small print but it's still useful.