The mirror addresses for Yours For Good Fermentable.com — www.yfgf.biz and www.yfgf.us — are hosted by GoDaddy.com. As of 6:11 this morning, it appears that GoDaddy's servers are down and out, or at least suffering massive failures.
The principal address at www.YoursForGoodFermentables.com is hosted by Google and so has not been affected.
I apologize for any inconvenience. [UPDATE: As of 10am ET, things seem to be back to normal.]
Maybe a larger point is as David Turley of Musings Over A Pint said (at my Facebook page):
We're reminded that no matter how large and pervasive 'the internet' becomes, it remains a chain of weak links.