Simple sugars, Mash temps & FG issues

[aboman]

I really like Brewersfriend and use it as my primary recipe editor. There is an issue that is starting to annoy me quite a bit however.

When adding simple sugar to a recipie Brewersfriend shows all of OG, ABV and FG going up. That is wrong, simple sugars ferment out virtually 100%, thus OG and ABV should go up, while FG should go down, signifying a thinner more attenuated beer.

Mash temp should also affect the FG, mashing at 156 for 60 min will yield a beer with higer FG than if you mash at 146 for 90 minutes.

These are things that beersmith 2 seems to get right, or at least it tries. Brewersfriend really should also get this right so we don't have to adjust the 'custom attenuation' based on experience when designing recipes.

I'm editing a recipe right now that Brewersfriend estimates a FG of 1.018 for, I'd expect this beer to be around 1.010 to 1.012 or so from experience. Beersmith estimates 1.009 that is a lot closer to reality.

 

[Ozarks Mountain Brewery]

agreed, most of the ending gravities I achieve are lower than the site tells me, I just chalk that up to a good brew day but I think it really needs to be looked at

 

[Josh (Brewer's Friend)]

Hi guys, you're definitely right that the fermentability calculations could use some love. I'm adding these changes to my list of things to do; I'll look into:
1. adjusting fermentability based on composition of fully fermentable sugars
2. effect of mash temperature on fermentability
3. effect of mash thickness on fermentability

I'll look into these as soon as I can; stay tuned for updates to these calculations. Thanks for posting the feedback!

 

[aboman]

Thanks!