I started a brew again last weekend. I am brewing a Belgian Dubbel recipe, but I hopped it a little more than normal, for a little longer than normal, and I added 50% more sugar in the form of Belgian Dark Candy and after 6 days, fermentation is still going very strong.
It did slow down considerably on day 4, but following the advice of some folks that post to various message boards, I re-pitched with some new yeast that I'd been culturing for a couple of days just as it seemed that fermentation was coming down off the peak and it seemed to regather strength quickly.
My original gravity was a staggering 1.083 - the highest I've ever tried to brew. My yeast strain should get an attenuation ratio around 80%, which would give me a final gravity of 1.016 and a 9.1% ABV in my final product. That's not a HUGE amount of alcohol for a Belgian, but it's more than I've been able to get before.
I'm even flirting with the idea of pitching some champagne yeast in another day or two to try to get more attenuation.
I don't want an overdry beer, but I don't want a sickly sweet one either.
This will be an interesting experiment, and I plan to culture the yeast for both bread and beer when I'm done as well.