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General Category => General Homebrew Discussion => Topic started by: Lazy Ant Brewing on September 03, 2017, 03:08:50 PM

Title: Spices affect IBUs
Post by: Lazy Ant Brewing on September 03, 2017, 03:08:50 PM
According to an article titled Understanding Bitterness by Stan Hieronymous in the Aug-Sep issue of Craft Beer & Brewing, adding spices can change both the actual IBUs and the perception of bitterness in beer.

Trials conducted several years ago by the Boston Beer company included adding 3.8 grams per liter of several spices for seven days to a base beer calculated to have 20 IBUs.  Spices used were coriander, cocoa nibs, dried lemon peel, coffee beans, and cinnamon, and were added individually.

The control sample measured 26 IBUs.  IBU levels for some of the rest were as follows: coriander, 27; cocoa nibs,24; coffee beans, 29; and cinnamon a whopping 80 IBUs.

More amazing was the perception of bitterness by twelve trained tasting panelists.  Despite the massive increase in IBUs measured by lab equipment from the addition of cinnamon, three of the twelve didn't find it more bitter.  And the panelists split on their perception regarding the cocoa nibs addition: six rated it more bitter and six less bitter.

The author did point out the an individual's genetics play a role in how tastes are perceived.

The above covers only a small portion of the topics and useful  info in the article.  I urge you to read it for yourself.
Title: Re: Spices affect IBUs
Post by: mabrungard on September 03, 2017, 03:55:30 PM
I don't really agree that spices are affecting IBU's. But I do agree that they will affect the perception of bittering. That is mostly due to the 'dryness' that most of those spices impart. This is much like the effect of adding sulfate to your water.

The bittering from hops or from some other sort of spice is a counter to the malt in the beverage. Those counters include iso-alpha acids, acidity, roast flavors, sulfate, and spice flavors. 
Title: Re: Spices affect IBUs
Post by: hopfenundmalz on September 03, 2017, 04:00:33 PM
Did they do lab tests? I don't subscribe to that magazine, but I have been thinking about signing up.
Title: Re: Spices affect IBUs
Post by: dmtaylor on September 03, 2017, 04:08:57 PM
The IBU is a laboratory-determined absorbance of light through a small sample of the beer.  Other things can absorb the light besides isomerized alpha acids.  It is possible that the spices are doing this to the beer, even though it won't taste any more bitter.  So, the IBUs are what they are, but they might not always necessarily be what we think they should be!  We need to understand that nothing about the lab methods or calculation of IBUs is perfect.  None of it.  It's just a tool, which can be flawed under many circumstances.
Title: Re: Spices affect IBUs
Post by: hopfenundmalz on September 03, 2017, 04:46:58 PM
The IBU is a laboratory-determined absorbance of light through a small sample of the beer.  Other things can absorb the light besides isomerized alpha acids.  It is possible that the spices are doing this to the beer, even though it won't taste any more bitter.  So, the IBUs are what they are, but they might not always necessarily be what we think they should be!  We need to understand that nothing about the lab methods or calculation of IBUs is perfect.  None of it.  It's just a tool, which can be flawed under many circumstances.
That is why HPLC is used, if a brewery can afford it.
Title: Re: Spices affect IBUs
Post by: denny on September 03, 2017, 04:59:30 PM
I don't really agree that spices are affecting IBU's. But I do agree that they will affect the perception of bittering. That is mostly due to the 'dryness' that most of those spices impart. This is much like the effect of adding sulfate to your water.

The bittering from hops or from some other sort of spice is a counter to the malt in the beverage. Those counters include iso-alpha acids, acidity, roast flavors, sulfate, and spice flavors.

THIS^^^^
Title: Re: Spices affect IBUs
Post by: jeffy on September 03, 2017, 07:02:21 PM
I put some caraway seeds in my Rye APA as a dry spice last week and noticed a significant increase in the bitterness.
Title: Re: Spices affect IBUs
Post by: Lazy Ant Brewing on September 04, 2017, 02:17:35 AM
Did they do lab tests? I don't subscribe to that magazine, but I have been thinking about signing up.

The article said , "The IBUs in the control sample measured 26," and then gave measurements for the others I quoted.  Do measurements imply lab tests?
Title: Re: Spices affect IBUs
Post by: hopfenundmalz on September 04, 2017, 01:45:58 PM
Did they do lab tests? I don't subscribe to that magazine, but I have been thinking about signing up.

The article said , "The IBUs in the control sample measured 26," and then gave measurements for the others I quoted.  Do measurements imply lab tests?

Yes, they probably did the photspectrometer standard test. There is a ASBC procedure for that. It gives accurate results for what it was developed on, which were the American lagers of the 1960s. Other compounds in the beer can absorb the light, giving readings that are not due to ISO-humulones.
Title: Re: Spices affect IBUs
Post by: Lazy Ant Brewing on September 05, 2017, 12:49:31 PM
The IBU is a laboratory-determined absorbance of light through a small sample of the beer.  Other things can absorb the light besides isomerized alpha acids.  It is possible that the spices are doing this to the beer, even though it won't taste any more bitter.  So, the IBUs are what they are, but they might not always necessarily be what we think they should be!  We need to understand that nothing about the lab methods or calculation of IBUs is perfect.  None of it.  It's just a tool, which can be flawed under many circumstances.

The article did acknowledge that trying to measure IBUs is problematic.  Personally, I know very little about hops, but I posted some of the info from the article to get a discussion started. 

I appreciate everyone's input.
Title: Re: Spices affect IBUs
Post by: mabrungard on September 05, 2017, 03:11:46 PM
The book on Session Beers that was just published by Brewers Publications had a discussion on bittering and perceptions. I don't recall the details, but the book did cite journal articles that indicate that bittering from hops is also due to substances other than the typically measured iso-alpha acids. I seem to recall a name like humulonene or something like that. I think the book used the term "tongue puckering" or something like it to characterize the undesirable nature of that form of bittering contribution.
Title: Re: Spices affect IBUs
Post by: denny on September 05, 2017, 03:53:02 PM
The book on Session Beers that was just published by Brewers Publications had a discussion on bittering and perceptions. I don't recall the details, but the book did cite journal articles that indicate that bittering from hops is also due to substances other than the typically measured iso-alpha acids. I seem to recall a name like humulonene or something like that. I think the book used the term "tongue puckering" or something like it to characterize the undesirable nature of that form of bittering contribution.

Humulinones, which are oxidized alpha acids and are s;lightly bitter.
Title: Re: Spices affect IBUs
Post by: zwiller on September 05, 2017, 04:26:07 PM
This effect is from polyphenols.  Cinnamon is classic.  Interesting it actually affected measured IBU that much but make sense.