Consistently missing Beersmith FG Target

[rayfound]

So, I am consistently missing my FG target in Beersmith by .003-.006.

Belgian Dubbel (Jamil's recipe) - Beersmith projected 1009, finished at 1012. WLP530 - Ramped temps to 74 Finish.

Belgian Quad - Beersmith projected 1009, finished at 1012. WLP500. Ramped temps to 80F Finish.

Amber Saison - - Beersmith projected 1010, finished at 1016. WLP568. Ramped temps to 92F finish. (Fast Ferment test on stirplate got this wort/yeast to 1.013)

These are all-grain brews.

I'm batch sparging and getting decent (70%) Efficiency.

My Hydrometer reads a perfect 1.000 with RO water.

I'm on 1L - 2L starters on a stir plate, and all have had vigorous, apparently healthy fermentation.


My thermometer is VERY slow (15+ seconds to stabilize on a temp) to get to temp... so getting strike water/mash temps dialed in is my main concern. Anything else I should look at as possible causes?

Thanks folks.

 

[BridgeBrew]

The Beersmith FG is a approximate number, not a definite one. Things such as your mash temp and how efficient you were at getting the sugars out of your mash tun will have a big effect on your FG. You seem to have a good system going, so don't sweat I too much and maybe keep a closer eye on your mash temps. If you are a bit high on your mash temps that can lead to higher FG numbers.

 

[freisste]

The Beersmith FG is a approximate number, not a definite one. Things such as your mash temp and how efficient you were at getting the sugars out of your mash tun will have a big effect on your FG. You seem to have a good system going, so don't sweat I too much and maybe keep a closer eye on your mash temps. If you are a bit high on your mash temps that can lead to higher FG numbers.

+1. Especially if OG is on target. That would mean you are getting the RIGHT amount of sugar, but you are off on fermentable percentage.

If your OG is off, you are getting more sugar out of the mash, so your attenuation may be perfect, but you have a stronger brew.

 

[GrogNerd]

not sure on the specific computations going on behind the scenes in BS2, but Estimated FG is based on Min and Max Attenuation in the yeast used for your recipe.

double check that the values for your yeast match the manufacturer's numbers

 

[rayfound]

I should also not the OG of these brews is 1073 Dubbel, 1072 Saison, 1093 Quad.


Yeah, i get that it is only an estimate. Mash temps were my only real suspect. Plan on buying a more accurate/faster thrermometer. My best guess is that I am running a little warmer than the actual temp, since it takes so long to stabilize.

Hitting OG is no problem, though generally I am coming in a little higher due to increased boiloff - but I adjust the original parameters to match the observed, so I get the updated FG estimate based on the actual results.

I think my biggest complaint is that this has an impact on recipe formulation. I'm adjusting recipes to get to a particular FG - then when it comes time to ferment, I miss it by a few points.

The saison is my most worrisome, since 1016 is pretty much outside of style. I did add 40+ IBUs, so I am hopeful that it will still strike a nice balance, being amber in color, it was never intended to be strictly within style.