Measuring IBU

[Woolsocks]

Looking to get a better grip on how many IBUs my beers have and what kind of hop utilization I'm getting.

Is there a relatively cheap way to do this? I see spectrophotometers on eBay for a few hundred bucks, but don't know what kind I need.

[JoeV]

You need a UV spec ~275nm for this. There is also a lab that does this kind of testing http://www.analysislaboratory.com, and last I checked it was less than $10 a sample. I would imagine it would take a lot of testing to justify the cost of UV/vis spec, reagents, glassware and time to learn how to do the test unless you are already familiar with the instrument. Although the test will give you a number, the "percieved" bitterness of the beer can be different than the "tested value". So maybe a panel of tasters would be a good option?

Hope this helps,
Joe

[Woolsocks]

Cool! That's easier than doing the test myself. Just out of curiosity, what kind of $$$ would I expect to lay out to get a UV spec ~275nm?

[Brew'n4U]

I remember those UC Davis days all too vividly...the spectraphotometer is the easy part of the experiment, I'm pretty sure you need a countertop centrifuge too. The chemicals and solvents needed to do the emulsification, the glassware and pipets, etc. are all a lot of stuff to acquire for a test you really only need to run quarterly to spot check your standards IMO

Give the lab their $10 and enjoy a few hours of not doing your own...

Steve
Lone Peak Brewery

[Øl-sheik]

You certainly wanna ask the lab to do the analyze, they do it cheaper and by far more accurate:

to measure alpha or bitter acids spectral photometrical you have to extract the bitter substances out of your acidified sample, remove disturbing factors by washing the archieved extract with acidified methanol and measure the concentration of the alpha acid in alcalinic methanol at 255 and 360 nm. the frequence on a spectral photometer is normaly always adjustable. i guess you get the idea that the lab is the better choice although you could use the photometer for so much more..