Using sourdough starter: "One cup" of risen or non-risen starter?
I have a very simple question but after searching all over the internet and reading tons of sourdough pages I can't find the answer.
I have a sourdough starter I've been feeding for a couple weeks but have not yet used in bread. I want to finally make my first loaf, but every recipe I look at calls for "one cup" of starter. The problem is, I don't know if that means one cup when the starter is risen, or when it is not risen. In other words, my starter is one cup when I've just fed it, and doubles to two cups--so, to take "one cup" from it when it is doubled would be to take half of it, though to take one cup when it is not doubled would mean to use all of it.
Obviously, if I want to keep the starter going and not use all of it, then I would need to increase the size of the starter before using it if I am indeed supposed to use one non-risen cup. Whereas if I am supposed to take half of the starter at the point when it is risen to two cups, I can go ahead and use it as is.
Thanks in advance to anyone who can answer this simple (stupid?) question. Since I haven't been able to find anything about this online I assume I'm somehow the only person who is confused about this point!