Tech: Finding Bitterness

Hops, we know them, we love them, but what exactly is it they bring to the party?  That is a rhetorical question really, we should all know by now that hops bring the magic of bitterness to what would be a sweet boozy treat.  IBUs or International Bitterness Units are the standard that we use to tell us just how bitter a beer will be.  As arbitrary as the number actually is, without a frame of reference it really doesn’t tell us much.  Of course, here comes the big turn around.  The subject we are exploring here is actually not how different beers stack up in the IBU arena, but how we find the bitterness level and what contributes to it. 

There are two acids that affect the bittering quality inside a hop flower; alpha and beta acid.  Alpha acids fall in the humulone family and beta acids fall in the lupulone family.  Without getting too geeky just know that the fresher the hop the better the alpha acid.  The older the hop the stronger the beta acid (fairly simplistic view but in a nutshell).  The reason this is important is that more flavor and aroma notes fall into the alpha acid family.  In the grand scheme of beers, this essentially means that great hop aroma and hop flavor in your beer is even better when the hops are fresher.  You can get some bitterness from young or old hops but bitterness alone will not define the character of the beer. 

It has been viewed that the Pacific Northwest is the power house of craft brewing in the US.  Part of the reasoning behind this has been the community of hop farmers inside this region.  For quite some time this was one of the largest suppliers for fresh hops for all of the US.  For Michigan breweries this meant receiving hops any where from 2 months to 6 months (or worse) from the time of harvest.  Definately not within a fresh range for alpha acid utilization. 

Success in one area brings growth in other areas.  With the growth of the Michigan beer seen we find a greater need for fresh hops.  This information really isn’t new (I love talking about the hop farms, especially the ones near me like Hop Head Farms).  With the growth of these farms we encounter a need to monitor the levels of alpha and beta acids within the hops.  At the same time a need arises to test different flavor keytones but the fun thing is this is also an affect of the terrior.  Soon the beers in Michigan may be showing a slightly different flavor notes that we don’t find in beers from other regions with the same breed of hops. 

The real question arises in how do we do these measurements?  You could have a brewer on hand to brew a few beers and then let your taste buds do the calculations.  But then that would be not only time consuming but very subjective, bringing no true definitive results. 

The use of recipe formulation software does a great job of laying out the details of the final beer but these numbers are just estimates. They are based on known paramators. Imagine what happens when something as simple as the boil kettle changes. To make it more difficult, I found out recently that there are different schools of thought for the calculations for hop utilization. The different software packages seem to use different formulas.

In the end, actual bitterness and perceived bitterness are two different things. The multitude of formulas that are used for finding the bitterness level of a beer at most are only estimates of what the actual bitterness might be. Professional breweries just as home breweries build a certain house character. This is determined by all the little variables that the software is unable to factor in.  The only way to know the actual bitterness of a beer is to send it to a lab. 
As it turns out, in Kalamazoo, Michigan there is one lab up and running right now that not only is able to do these tests but also test every aspect of the finished product as well (the beer using the hops).  Kar Labs has an extensive background in environmental analytical chemistry, which works well with the testing needed for hops and beer.  They started their hops program during the spring of 2012. 

Through an email conversation with Andre Venter from the chemistry department at Western Michigan University it was found that they are working to set up a hop lab as well.  They are hoping to have their lab up and running shorly after November, starting with analyzing alpha and beta acids from hop bracts and pellets.  They do plan to expand into aroma profiles and varietel typification as well.  (Sadly, they don’t have a website yet for this aspect to check out what services they will be offering)

Time for a pint…

One thought on “Tech: Finding Bitterness

  1. Pingback: WMU Bitterness Lab – 10th Day Brewing

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