Originally Posted by marcobrau
A lower gravity (1.036-1.048) homebrew made in a single stage fermentation (single fermenter) can taste just as good as some commercial microbrewed ales. Sanitation is more important than secondary fermentation. I use a secondary fermenter when I need to ferment a beer longer than 14 days (usually a stronger beer). I also use the secondary for dry hopping. If you are unfamiliar, this is adding dry hop pellets to the secondary for added hop aroma. Lagers need to be racked to a secondary to complete fermentation and to separate the fermenting beer from the yeast cake for a cleaner flavor.
I don't have much experience yet but from what I have read and have tried you can ferment in the same vessle for up to 3 weeks without risking off-flavors.
The more fermentables you have in the brew the longer it will take for the yeast to ferment and settle and you absolutely want the yeast to settle before you bottle or you have yummy yeasty beer.
Also racking into a second fermenter you risk infecting your beer. I would say only hard-core brewers should screw around with secondary stage fermenting. You can bassically acomplish secondary fermentation in the bottle by condition for a few weeks after bottling and before drinking.