Beersmith Brix Calculations

[ECH]

Need some tutoring with Beersmith.

Got a saison going at the moment, used YB Wallonian Saison.

OG of 1.056, refractometer is calibrated, and entered into BSmith. However when I use an online Brix conversion, I am currently getting and SG reading of about 1.024, which works out to about 4.07% ABV, meanwhile in BS, if I plug in the OG, and enter the current Brix reading it is telling me it is 6.82% ABV. (in the refractometer part under "Fermenting Wort Gravity")

However if I go to the SG calculator on BS, and enter in the OG and the current gravity, it tells me it is at 4.2% ABV

I think it is just my lack of understanding of some of the intricacies of BSmith, but thought it was fairly straight forward for this part, but needless to say, I am a bit confused.

First time using this yeast as well, so not really sure how long it should take to ferment out. Have a heating pad on the side of my fast ferment on high, so it sitting at about 82F/27C

It has dropped 0.2brix since Friday when I checked it last so still coming down, and has been in the FF for about 9 days. Yeast obviously needs longer to go, as everything else I am reading they are saying 14-18 days in primary.

[Two Wheeler]

I got some funny readings the last time I tried to use the refractometer and calculator for fermented beer. I think (unfortunately) the hydrometer is the only reliable measure at this point.

[ECH]

Refractometer works fine, just BSmith calculations

[blisster]

I've tried several different calculators for checking the FG based on refractometer readings and always had questionable results. 

When comparing the calculated FG results with the hydrometer one, it would sometimes be off by a couple of points or more (above or bellow) and other times it was spot on. 

It might have been something I was doing wrong but decided to stick with the good ol' hydrometer for RG readings for peace of mind... I'll trust that over a calculation any day 

[JamesPonting]

The challenge with the refractometer is that all dissolved solids will impact the refractive index (Brix) measurement.  When the concentration of sugar is much higher than any other dissolved solids (eg in your wort), the error is low and the refractometer will provide a good estimate of the sugar concentration (potntial alcohol).  After (and during) fermentation, the sugar is being converted into alcohol and CO2.  The alcohol will impact the refractive index (Brix measurement) and not to mention any other dissolved solids will also be a source of error.

Bottom line is that a refractometer is pretty good tool for measuring initial sugar concentration (which you an correlate to SG).  A hydrometer is a better tool for measuring FG. 

https://www.northernbrewer.com/connect/2011/08/using-a-refractometer/