The Effect of Final Gravity on Finishing Sweetness

[so2002]

Hi guys,

First time poster, long time lurker. I've brewed 10+ times and am starting to experiment with my own recipes. I realize that I still have a ton to learn and am curious about brew theory.

I am well aware of the Bitterness Ratio, that is Bitterness Units / Gravity Units. The higher the Original Gravity, the more IBUs you can pump into the beer without it seeming bitter. But isn't there going to be more to the perceived bitterness than just the OG?

Final Gravity lowers as the fermentable sugars are churned into alcohol. Higher FG corresponds to a sweeter finished beer. Is it wrong to assume that a higher final gravity will also counteract the bitterness of a beer, as it balances bitter with sweetness (vs bitter with booziness)?

Example:

1.071 OG
43.5 IBU
.615 Bitterness Ratio
1.020 Est. FG

My gut tells me that if this beer finishes at 1.020 that it will be too sweet and that it requires more IBUs to balance it out.

Mike

 

[shanecb]

You're correct, a higher finishing gravity does tend to favor needing a bit more bitterness to have the same general perceived bitterness.

 

[Hujo]

Well yes, but it depends. If the "high" FG of 1.020 is a result of a hot and short mash - long chain sugars, it will not be percieved as sweet but rather as full. There is still an effect on the percieved bitterness, but not to the same extent as a high FG caused by a low attenuating yeast or excessive use of crystal malts, which will come across as sweet. Now if you have a high FG as a result of (or in part result of) a high percentage of non-sweet specialty malts, like roasted malts etc, you might increase the percieved bitterness because of the roasted and or dry character that said malts impart.

So yeah, you're correct, there are just a lot of factors at play.

 

[raysmithtx]

There's a pretty good calculator here which takes the OG and the FG into account when calculating the bitterness.

 

[Qhrumphf]

There's a pretty good calculator here which takes the OG and the FG into account when calculating the bitterness.

http://www.madalchemist.com/relative_bitterness.html

Similar idea (and from the same source as the link above). Weights the BU:GU of a beer, and your apparent attenuation against "average" apparent attenuation.


There's a load of factors, as has already been said. And it's not just gravity that impacts sweetness, but the actual flavor as well. For example, my house Mild has apparent attenuation of only about 60% (high mash, lots of specialty malts) and low bitterness, but comes across as relatively dry, since a fair amount of roasted dryness balances the sweetness, instead of hop bitterness.

On the other hand, I made a Maple Wine (think mead but using maple syrup instead of honey), that went from ~1.080 to ~0.990, ie bone dry from a residual sugar perspective, however due to the intense flavor of maple, it still had a cloyingly sweet flavor, despite having almost no residual sugar. Here, it was probably a combination of the flavor memory that the brain associates maple syrup with sticky sweet, and likely also the high alcohol having a sweetness to it too.

So you're right. Lots of things at play. But yes, a beer with the same OG and same IBUs that finishes at a higher FG than an otherwise identical beer would more than likely be perceived as less bitter.