Summary: All attempts to accurately quantify beer balance objectively before brewing will fail because of the many contributing factors. For example, grain bill (some things that aren’t hops are bitter), attenuation (difficult to calculate before fermentation), carbonation, etc.

Perhaps instead of attempting to predict balance more accurately than BU:GU already does, it would be valuable to codify balance for what objective data we DO have access to–but to direct those efforts toward expanding our ability to communicate with other brewers about an existing beer rather than using it to help define a recipe upfront.

Meaning, let’s come up with a useful number so I can go over to the AHA conference and say, "Hey, try my beer. Its perceived bitterness is 5, so it’s well-balanced. I have some roasted barley in there too, which increases the astringency a little, but check it out!"

My intent with spending all the time working on this article was largely to start a conversation on finding ways to predict and target beer balance. I’m glad the conversation is starting.

Ultimately, the best way to make the beer you want is to brew it once then make corrections in pursuit of your intent, but I’m always interested in methods to frontload that effort with calculations (the fewer repetitions needed to perfect a recipe the better).

The Mad Fermentationist (not me, I’m the Mad Alchemist!) emailed me and proposed that we start thinking along the lines of the residual extract (which I believe is the same thing as real extract, so that’s what I ran with).

To push this discussion further along, here’s some thoughts I sent him about that approach.

I added columns for Real Extract in both Plato and Specific Gravity to the far right of the data chart.

https://docs.google.com/spreadsheet/ccc?key=0Ai1Yv492QZYUdFN1YWpYZTFxUm1reWN2WEx2a0xpUkE

I originally used RDF (Real Attenuation) instead of ADF (Apparent Attenuation) for similar reasons. Ultimately, since I decided to adjust the Balance according to a beer relative to all other beers, using ADF vs. RDF became inconsequential (because your beer’s RDF in comparison to the average is the same as your beer’s ADF in comparison to the average). I switched back to ADF so people didn’t have to bother with RDF = ADF * 0.8192.

Real Extract is a similar approach, though might be more accurate in terms of perceived sweetness of the final beer.

If we were to decide to create a new number scheme from BU:GU entirely, I think it might yield some useful results (part of my decision to go with what I did for RBR was to make it more accessible since many people are familiar with BU:GU already, and the numbers are essentially the same).

Anyway, I also dropped in a thought on a potential method to calculate this under "BU:RE" in the last column.

It is IBU/RE (°P)

International Bitterness Units / Real Extract (degrees Plato)

Real Extract (RE) = (0.1808 × °P_initial) + (0.8192 × °P_final)

Interestingly, this (IBU/RE (°P)) gives numbers roughly on a scale from 1 to 10, with the outlier being Imperial IPA at 13.4. It’s actually the only beer style above 10 using this equation.

I went ahead and colored the columns as well, which allows us to see that beers relative to one another look roughly the same as BU:GU and RBR.

I’ve added some data to the chart for us to look at:

• "BU:RE (°P)": Bittering Units/Real Extract in degrees Plato
• "BU:REU (SG)": Bittering Units/Real Extract Units in Specific Gravity (Real Extract Units = (SG – 1) * 1000)
• "BU:FG (°P)": Bittering Units/Final Gravity in degrees Plato
• "BU:FGU (SG)": Bittering Units/Final Gravity Units in Specific Gravity(Final Gravity Units = (SG – 1) * 1000)
• "BU:FG (SG)": Bittering Units/Final Gravity in Specific Gravity

Light American Lager and Gueze both get a little broken because their average FG is actually less than 1 °P (unless you look at the Real Extract numbers, which look a bit better).

My favorite of the bunch is BU:RE (°P). The numbers make my brain happy because it is basically on a 10 point scale. The average of all beer styles is 5.4, so I suppose it could be corrected to make 5 be dead average, but that’s just manipulating the data to make it prettier.

The formula looks a little nasty if you don’t break it up into its constituent parts.

Effectively it is just IBU / RE in °P.

Real Extract (RE) = (0.1808 × °P_initial) + (0.8192 × °P_final)

If you want to write the entire thing out into a formula using Standard Gravity (since most homebrewers use SG and not °P)… Well, this is going to look nasty in forum text, but I’ll attempt to write it out.

(IBU / ((0.1808 * (259-259/OG)) + (0.8192 * (259-259/FG))))

Yeah, looks nasty. Hooray for calculators. This includes the conversion of SG to °P right in the equation for both OG and FG. It also includes the conversion from FG to Real Extract in the equation. It certainly looks like a mess, but the results are elegant and seem pretty accurate to me on a 10 point scale.

This still suffers from the need to either measure your FG or try to predict it accurately if using it to formulate a recipe. Perhaps it would be more useful when communicating with each other as to the balance of our beers rather than in planning a recipe.

"Here, I brewed up this Irish-American Red. Its BU:RE is around 7, so it’s more bitter than your average Irish Red. I lovingly call it the South Boston Red. What do you think?"

"Try my Imperial IPA. It’s got a BU:RE of 9, so it’ll taste a little less bitter than you might be used to in such a bitter style. I call it Archduke IIPA. Got enough bite for ya?"

The Mad Fermentationist (not me, I’m the Mad Alchemist!) emailed me and proposed that we start thinking along the lines of the residual extract (which I believe is the same thing as real extract, so that’s what I ran with).

To push this discussion further along, here’s some thoughts I sent him about that approach.

I added columns for Real Extract in both Plato and Specific Gravity to the far right of the data chart.

https://docs.google.com/spreadsheet/ccc?key=0Ai1Yv492QZYUdFN1YWpYZTFxUm1reWN2WEx2a0xpUkE

I originally used RDF (Real Attenuation) instead of ADF (Apparent Attenuation) for similar reasons. Ultimately, since I decided to adjust the Balance according to a beer relative to all other beers, using ADF vs. RDF became inconsequential (because your beer’s RDF in comparison to the average is the same as your beer’s ADF in comparison to the average). I switched back to ADF so people didn’t have to bother with RDF = ADF * 0.8192.

Real Extract is ultimately a similar approach, though might be more accurate in terms of perceived sweetness of the final beer.

If we were to decide to create a new number scheme from BU:GU entirely, I think it might yield some useful results (part of my decision to go with what I did for RBR was to make it more accessible since many people are familiar with BU:GU already, and the numbers are essentially the same).

Anyway, I also dropped in a thought on a potential method to calculate this under “Perceived Bitterness?” in the last column.

It is IBU/RE (°P)

International Bitterness Units / Real Extract (degrees Plato)

RE = (0.1808 × °Pinitial) + (0.8192 × °Pfinal)

Interestingly, this (IBU/RE (°P)) gives numbers roughly on a scale from 1 to 10, with the outlier being Imperial IPA at 13.4. It’s actually the only beer style above 10 using this equation.

I went ahead and colored the columns as well, which allows us to see that beers relative to one another look roughly the same as BU:GU and RBR.

Melissa & Chris

Happy Brewing!

-JW

I was thinking of just adding the roasted barley right before runoff so I don’t tie up another vessel (or maybe steep in a bag in the wort during runoffs).

Your thoughts?