Author Topic: problems with estimated FG/ABV  (Read 1394 times)

Offline Beezer94

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problems with estimated FG/ABV
« on: May 10, 2017, 11:25:55 AM »
I've noticed two seperate problems with estimated final gravity.

1. If you have a recipe and you add your first yeast, it ignores attenuation of subsequent yeasts.  For example you add a lower attenuation yeast like WLP002 first and then add WLP001 it only uses the WLP002 to estimate FG.  It should be using the highest attenuating yeast for this calculation.

2. If you select a mash profile such as 'BIAB- Pilsner step mash' it seems to show that you will have the good attenuation expected in the estimated final graviy.  The problem is if you have 2 temperatures in the step mash that are both in the saccharification range, the estimated final gravity and estimated abv ignore the lower temperature part of the mash.  For example you have one step at 145F for 60 minutes and another step at 155F for 10 minutes, it bases the FG estimate only on the 155F step.

Offline BeerSmith

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Re: problems with estimated FG/ABV
« Reply #1 on: June 05, 2017, 06:04:19 PM »
  I'll make note of item (1) and try to correct that.  Item (2) I actually did correct for an upcoming version of BeerSmith which should be out this fall.

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Offline prolific

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Re: problems with estimated FG/ABV
« Reply #2 on: June 13, 2017, 01:46:26 PM »
Oh man, please do fix this.  It has bugged me for the last year.  I've just been using the 'measured OG/FG' fields to at least have some way to estimate the ABV prior to fermentation while trying to design a beer.

I do a lot of temperature raising in mashes for my lagers from 133, to mid 140s and midtoupper 150s... beer smith doesn't seem to be able to handle it.  I also like to do Hochkurz decoctions, but again I don't know if Beersmith is able to estimate the efficiency/FG when I have all of these crazy raises in place.
However just to temper the above feedback, I REALLY love this software and all it has done for me and everyone else out there.  Please keep up the great work!

Offline tlaffey

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Re: problems with estimated FG/ABV
« Reply #3 on: July 10, 2017, 03:23:32 PM »
I sent a support request via your website earlier today. This is a follow up. I?m using BeerSmith 2.3.7.

Using my hochkurz profile, I cannot get predicted FG below 1.020. As you can see in attached screen grabs, the current profile estimate is FG 1.020 and therefore the ABV is only 5.9%. This appears to be a bug, since using the same temp and time with a single infusion profile (145*F, not 148*F) yields FG of 1.009 and ABV of 7.3%. IMO, these values should be quite close to each other. Please advise.