Originally Posted by kcross13
I was getting different readings from Brewsmith and from my distributors site. Curious.
Well, Beersmith gives you a "standard" attenuation %, no matter what the mash temp or the ingredients. If you plug in 100% corn sugar, or 100% crystal malt, you'll get the same projected FG in that software. So, their FG projection is simply NOT ever accurate.
FG is more than just a simple % of fermentables, although you can guess close with a percentage. The thing is, crystal malt is less fermentable than, say, two-row. And combine that with a very high mash temp, you'll have more "long chained" sugars which leave a less fermentable wort as well. So, usually guessing a FG is not hard, but it takes some practice with looking at mash temps, ingredients, and yeast strain to be able to estimate it closely.