Measured IBUs

[AnthonyCB]

I was wondering if any of you have made use of HopUnion's IBU testing service? I sent in a few of my commercial brews as well as a home brew batch out of curiosity. I thought it would be interesting to collect a few data points from other people who had analysis done on their homebrew batches.

I sent in a DIPA from a 21.5 liter (5.67 gallon) batch with an OG of 1.074 fermented with 2 packets of S-05
additions were as follows:
60g Summit 15.9% @ 60 mins
50g Simcoe 13% @ 30 mins
25g Columbus 14% @ 15 mins
25g Mosaic 12% @ flame out
25g Centennial 10% @ flame out
25g Amarillo 8.7% @ flame out

I get a strong boil on my system with typically in excess of 10% boil off per hour. As usual, I did a 20 minute hop stand after adding the flame out hops and cooled rapidly (3 minutes or so to get below 90F) to 65 F using my immersion chiller.

BeerSmith2 calculates 161.9 IBU (I understand that this exceeds the solubility of AA in wort and does not include the ~20% reduction in IBU that you see as a result of fermentation and yeast flocculation).

Hop union came back with a reading of 64.9 IBU on a 2 month old bottle conditioned sample which seems reasonable to me.

Anyone else out there with readings to post?

-Anthony

 

[ajdelange]

I was wondering if any of you have made use of HopUnion's IBU testing service?

I run IBUs on all my beers. Not sure of how much interest the data would be to anyone except as a reflection on the degree to which one can predict using the popular models and the data that appears on the hops bag. The individual circles plot the difference between the predicted IBU and the actual IBU realized as a percentage of the predicted IBU. The predictor was the Tinseth model with its time parameter chosen to minimize the rms error.

Commercial operations who buy a large volume of hops from a single supplier and use it to make multiple brews over a period of time ought to be able to realize much better predictions or at least much better batch to batch consistency than the graphed data suggests.

 

[ncbrewer]

ajdelange: Interesting collection of data points. Were these all-grain batches, or were some extract? I'm wondering because of the recent debate over an actual correlation of hop utilization vs boil gravity, especially with extract beer.

 

[ajdelange]

These were all all grain batches mostly lagers and most with Saaz hops.

 

[chri5]

Out of curiosity what were the results from the commercial beers you sent in?

What's the price on the service? Their site has no pricing information that I can find. :-(

If it is reasonable I'm going to start taking advantage of it for a few tests.

 

[Oginme]

Interesting scatter diagram. Do you have a number of repeats of the same recipe/brew process? There is a grouping of points just under 40 IBU that could represent a repeat which would put the scatter range from about -25% to +22%.

 

[ajdelange]

I'd have to go back and look at logs to determine exactly what is what but there are, grouped around 40, quite a few Bohemian Pilsners but not everything grouped around 40 is a Boh. Pils. I do think ± 25% is a fair estimate as to what you can expect to get.