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> Local homebrew store owner today told me that the FG is roughly a certain %
> of the OG. Im curious, as Ive been making some of my own recipes now, and Im
> not sure what to look for as my target for FG. She said its about as good as
> it'll get, (OG 86, currently 20). Anyone have input on this?[/color]

It is only VERY ROUGHLY a certain %... because different extracts have different
amounts of fermentable vs. unfermentable sugars, and therefore, will ferment
down a different amount. This difference can be considerable. Also, some
yeast strains will ferment more aggressively than others. Another example
is that Lager yeast can ferment an extra type of sugar that ale yeast cannot,
therefore lager yeast should ferment a little further than ale yeast. Other
additives, like maltodextrin and crystal malts, will not totally ferment out
and, therefore, raise the FG higher than expected.

With all the variables, I don't think you can count on figuring the FG simply
by using a % of the OG. The only exception might be if you always use the
exact same ingredients and derive the % from experience.