Just read about this in Strong’s book and I admit I hadn’t ever heard of it before. My initial impression was that it made sense inasmuch as the bittering is perceived as part of the finished beer, not the wort. Of course its not necessarily a stand-alone value because a big, dry beer vs a big sweet beer are going to show bitterness differently. Presumably the sweet will balance a higher bitterness, whereas the higher ABV of the dry one will accentuate the bitterness. So I suppose we should be looking at both and getting in a range that is acceptable on both ends. Better yet, it’d be nice to combine the two into a single simple formula. Somebody should really work on that.
First question, who has been doing this math and what sort of value ranges are you finding to be preferable?
Second question, how do you utilize both paramaters so you cover all the bases?
I have my ideas but thought I’d listen to others’ opinions first since I really haven’t mulled this over much.
The BU:GU concept has been around for a long time (believe it was Ray Daniels in his Designing Great Beers first). As for calculating tools for it, it gets calculated for you in BeerSmith and probably other software.
Right, but the BU:FG ratio is supposedly a more recent development. Both are simple enough to do in your head or with a little calculator. And I think both have utility when it comes to designing a beer recipe. They really just put a number to what people already know, that there needs to be balance between the various sensory aspects of a beer.
I see what you are saying. The final taste results are more of a ratio between FG:BU rather than OG:BU. However, we, as homebrewers have more control over OG than FG. We can’t be sure what the FG will be, we can manipulate our grain bill for fermentabililty (Addition of simple sugars, specialty grains with varying levels of fermentability) and our mash temp and yeast selection but it’s difficult to estimate an FG accurately. Once we have a recipe down we can be fairly close but batch to batch variations in malt characteristics will still affect the FG in unpredictable ways.
Granted this is also true to some extent of the OG but at least at that we can easily manipulate with additional sugar (malt or simple) additions. Our choices to manipulate a FG post fermentation are limited to blending or adding other microorganisms.
All that being said I think it is a good idea to think about when tweaking a recipe that you have gotten to the point of fairly consistant FG readings.
I think the more experience we have over our process and materials, the more we can get a predictable FG result. Yes there are periodically surprises, but I’m doing pretty well at hitting an OG within a point or two myself. Of course I’m not making dozens of different styles. A point or two of FG does have a larger impact percentage-wise, than a point or two of OG. Still, I think it might pay to be aware that bitterness and FG have a relationship and as you quantify it with this simple ratio, you can start to calibrate your tongue.
Seems both OG and FG vs BU ratios could be useful and also misleading at times. A big Belgian that finishes at 1.008 is gonna need a lot more IBUs than a low gravity beer that finishes at 1.012 to achieve the same balance.
IME, yes. All that alcohol in the big belgian adds to the perception of sweetness even though it finishes lower. Even though the big Belgians are typ low in bitterness, it takes a lot more hops to achieve that level of bitterness than in a much smaller beer even if it has a higher FG.
Another consideration is that a 1.065 beer that finishes at 1.010 has more residual sugar than a 1.045 beer that finishes at 1.010, due to the lower gravity of the alcohol.
True, but residual sugar and ABV have sort of opposite effects on bitterness perception so that would bring the two back together to some extent.
All in all, these numerical representations are only going to take you so far. There’s still going to have to be some thought given to the individual circumstances which are different for nearly every beer recipe. I suppose the best thing we can say about adding BU/FG to the arsenal is that it brings some attention to the residual sweetness part of the beer and makes you think about the finished product.
This is a good measure to consider when building a recipe. I like the fact that it takes into consideration the OG and FG which incorporates the finishing body of the beer. This can impact the perceived bitterness.