That Amish solution sounds intriguing, I'll have to keep the recipe.
The life cycle of the fruit fly isn't very long, so if we have a swarm going, we just try to be diligent about taking the compost out every day. They're usually gone in a few days.
As for it being the middle of Winter, well, they've probably found a nice, warm, cozy place to hang out (and breed) in your kitchen! They're stoked!

But seriously, I don't think they can breed unless they have some food to deposit their eggs on, so take out that compost every day! (Or at least stick it outside the back door, I know tromping out to the compost pile every day in Winter can be a pain.)