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How does Beersmith calculate your FG? It seems low to me. I think I am going to go back to paper and just use beersmith as a rough guide.

Does anyone know a table out on the webs somewhere that has the ratio of fermentables to non-fermentables in typical malts? I know mash temprature has a lot to do with it, but even if someone has made a comparison table for a fixed temp it would be really handy.

I believe Beersmith calculates based on yeast attenuation.

jeffsmith wrote:I believe Beersmith calculates based on yeast attenuation.

So roasted barley is just as "fermentable" as 2 row?

Edit: assuming the enzymes are present for starch conversion.

mgc wrote:How does Beersmith calculate your FG? It seems low to me. I think I am going to go back to paper and just use beersmith as a rough guide.

Does anyone know a table out on the webs somewhere that has the ratio of fermentables to non-fermentables in typical malts? I know mash temprature has a lot to do with it, but even if someone has made a comparison table for a fixed temp it would be really handy.

Final gravity is calculated from attenuation, as Jeff said. I don't know about "ratios" but I believe the fermentable sugars are calculated from the "yield" of the malt - I don't have BeerSmith, but I'm sure all the programs are the same and will have "yield" as a percentage.

In my experience nothing can really accurately predict attenuation based on ingredients. There's so many other factors that experience and knowing your system are the best way. Even then you get a surprise once in a while.

mgc wrote:

jeffsmith wrote:I believe Beersmith calculates based on yeast attenuation.

So roasted barley is just as "fermentable" as 2 row?

Edit: assuming the enzymes are present for starch conversion.

No, the fermentable sugars in roasted barley are just as fermentable as two-row. So take a roasted barley with 55% yield, and 2-row with 79% yield and you'll get different results, but BeerSmith should be taking that into account. Of course, BBB's right that there are far more variables, but I'd trust the program before pen and paper.

+1. I tried to get beersmith to address this years ago. Unless it's been corrected, a 100% black patent grain bill gets calculated to the same fg as a 100% 2row grain bill. I just go by instinct and experience to judge my fg now. Too many variables to calculate as bbb alludes to.

Great! I just thought I was missing something simple about how many unfermentables are introduced into the wart from different types of malts. The more I read the more I realize "it just depends...". I will continue to take good notes and just see what happens as I gain more experience on my AG system.

So do Brew Smith take into account the fermentability of the wort you made?

I think it is hard for a program to take into account every variable that influences attenuation, but hey, what the heck do I know
about computer programs....

Tony L wrote:So do Brew Smith take into account the fermentability of the wort you made?

I think it is hard for a program to take into account every variable that influences attenuation, but hey, what the heck do I know
about computer programs....

Yeah, I thought there would have been some (non) liner equation, that modeled your mash temp and system parameters to the attenuation. Apparently not, but the more I read the more I understand why.

On a related note, maybe I will start a spread sheet and design such a model from our collective experiences (if you guys are willing to share your data) . That could be my summer project, but who knows if it will produce anything useful. The problem I see is lack of data points relative to the number of parameters affecting attenuation. I doubt its a linear system, otherwise it would have been done long ago, but I think a bagged decision tree (or something similar) would work well to give us an idea of what is doing what to the fermentablility of our beers. We wouldn't be able to say a mash temp of 2F higher yields X more FG points, but we could say that the bigger brew pot with a faster cold crash more often then not results in lower FG. Anyways, its just a thought.

Lots of great info and data here,out may find something of interest http://braukaiser.com/wiki/index.php?ti ... Ingedients" onclick="window.open(this.href);return false;

LiverDance wrote:Lots of great info and data here,out may find something of interest http://braukaiser.com/wiki/index.php?ti ... Ingedients" onclick="window.open(this.href);return false;

Yeah I saw that last night, good resource for sure. I think it would still be cool to see what factors have the biggest impact to the homebrewer.