Northern brewer recipe. I'm just learning the basics right now but since I started I can't keep my fermented empty. Lol kind of got hooked quick. Just bottled a dark cherry stout n I'm bottling a blonde ale in a few days
There are lots of threads debating this all of the forums. Most of the debate has to do with clarity rather than flavor though. You'll find a different opinion on this from just about everyone that answers.
I mix it up depending on whether the batch gets any dry hops or post fermentation flavoring and depending on if I'm harvesting yeast.
I usually do four weeks in a primary if I'm not dry hopping or harvesting, two weeks if I am. Totally up to you man.
You know what's cool about this hobby? It's not that costly (except time) to make a batch. You can try several batches both ways and decide for yourself which one you prefer. You definitely won't mess up your beer doing a 2 week primary/2week secondary or a full 4 week primary.
If the beer is left on the yeast for a little after it is done fermenting, the yeast will then go back and consume some of their undesirable bi-products they create during fermentation. The amount of time you would need to leave beer on the yeast to have negative effects is often debated, but it is safe to say it is greater than the 4 week period.
I go standard of 4 in the primary, sometimes if I am dry hopping I will go 3 and move it to secondary for the 4th to dry hop, sometimes I will just throw the dry hops in the primary right at week 3 for a week.