This starter has (theoretically) been handed down through the generations from the Amish themselves. If followed exactly, each recipe makes enough starter for several loaves. You're then supposed to share this excess starter amongst your friends and thus continue propagating the recipe.
Once you receive it, the starter has a 10-day cycle before it can be used to make your own loaf. During these 10 days, you alternately mush the bag (which distributes ingredients and invigorates the wild yeast) and add fresh ingredients to the bag.
The starter is actually fairly interesting. It's a combination of equal parts flour, sugar, and milk, which is unusual since sugar and milk are both things that slow down yeast production. Also, although the instructions say to leave the starter unrefrigerated, the milk doesn't seem to spoil - at least ours seems ok so far.
We're on Day 7 right now and are looking forward to making a loaf later this week. We've enjoyed a few samples from loaves friends have made, and we can attest to the yumminess of this bread.
Calling it 'bread' is a bit misleading, though. Light, moist, and flavored with cinnamon, it's really much more akin to cake! Not that we're going to argue about semantics when there's more nibbling to be done...
We admit to feeling rather uneasy about what to do with our excess starter. There's pressure to keep it going, but also a bit of social awkwardness about pushing it onto friends and family - it really is just like those chain letters back when we were kids!
What do you think about Amish friendship bread - fun, annoying, or just simply delicious?
Related: Ungift Guide: Beer Bread Mix