Custom Extract Profile On Beersmith 2.2.

[Greg2013]

I am trying to add a custom extract profile for the kit below to Beersmith however i don't know what IBU value i am supposed to enter on Beersmith.As you can see the 1.8kg tin gives an ibu range of between 17-23,however Beersmith asks for IBU per gal/lb,so what value do i enter on the Beersmith profile for this kit ?




http://www.homebrewwest.ie/muntons-connoisseurs-18-kg-bock-beer-kit-427-p.asp

[Parky]

Hi Greg,

A rough calculation here - assuming you're making a 23L batch, the IBUs are 17-23 for 23L/1.8kg - so I'll take the mid point in the IBU range of 20 IBUs for the calculations below -

First convert the L/kg value to imperial -

23L/1.8kg  = 6 US gallons/4lbs (imperial weight is rounded up from 3.96lbs to 4lbs for ease of calculation)

Next express the whole lot as fractions -

20/1(IBUs) = 6 US gallons/4lbs

Find the common denominator for the US gallons/lbs, and multiply the IBUs by the same factors (in this case multiply the numerator (figure above the line) by 2 and the denominator (figure below the line) by 3) -

40/3(IBUs) = 12US gallons/12lbs

Finally, divide the denominators into the numerators -

13.33(IBUs) = 1US gallon/1lb

So the answer to your question is - 13.33 IBUs per gal/lb