Ibu?

[eddy401]

hi,

can any one tell me how to work out the IBU of a brew? i have citra hops that are 11.1% AA, i would like to know the equation for working out the IBU so i can reverse it and get an IBU ive already decided on. or does this need fancy equipment?
id guess its something to do with the weight, AA, when you add the hops, maybe the malt amount/type??

thanks in advance

P.S - does anyone know the IBU of sapporo lager, or roughly what they think it would be? its about the same bitterness to taste that im aiming for with my next brew

 

[Aus_Rider_22]

There is alot of software floating around for free that can tell you these figures and much more.

I recommend checking out Beersmith or ianh's spredasheet. They will help you get an idea of your recipe specs. They are in my sig.

Happy Brewing.

 

[Shed101]

Sorry ... I can't help myself

>click me, click me<

 

[Nick JD]

P.S - does anyone know the IBU of sapporo lager, or roughly what they think it would be? its about the same bitterness to taste that im aiming for with my next brew

I would say 25 IBUs all from noble hops like Saaz and Hallertau with probably 10 of those IBUs coming from late additions.

 

[manticle]

According to Ray Daniels, the simplest equation is:

IBU = [Weight in grams multiplied by utilisation# (affected by boil times etc) multiplied by AA % rating multiplied by 1000]

DIVIDED BY

[Volume in litres (final volume, not pre-boil) multiplied by corrected gravity*]

OR (Wg x U% x AA% x 1000)/Vl x Cg

*Corrected gravity = 1 + [boil gravity-1050] divided by 0.2.
# Utilisation expressed as percentage

Weight in grams = (Volume x corrected gravity x IBU)

DIVIDED BY

(utilisation x AA x 1000)

OR: Wg = (Vl x Cg x IBU)/U% x AA% x 1000)

Obviously if using a prebittered kit you will need to add in the IBU of that.

Daniels does specify that these equtions are only effective for calculating the bittering from hops - flavour hop amounts will differ, even though flavour hops will add some bitterness which needs to be taken into account. He also mentions the complexity of working out utilisation factors for you, your brewery and even each brew.

 

[katzke]

hi,

can any one tell me how to work out the IBU of a brew? i have citra hops that are 11.1% AA, i would like to know the equation for working out the IBU so i can reverse it and get an IBU ive already decided on. or does this need fancy equipment?
id guess its something to do with the weight, AA, when you add the hops, maybe the malt amount/type??

thanks in advance

P.S - does anyone know the IBU of sapporo lager, or roughly what they think it would be? its about the same bitterness to taste that im aiming for with my next brew

Yes there is a way to do the math. It is not as easy as X times Y times Z, so it is best to use some kind of brewing software. If you must know how to do it I am sure you can find it in an advanced brewing book or by Googling the calculation of hop bitterness.

As I recall it is dependant on time and gravity as well as the AA of the hops and how much is used. An array is used to get the factor to use based on the time and gravity or something like that. Then there are several different methods to calculate the conversion.

As you may tell it is just easier to use software.

 

[ianh]

You could use a copy of my spreadsheet Link but you will need to add Citra to the Hop list on the main worksheet.

As I just posted elsewhere this is where I got most of my info from Hops

cheers

Ian