It'll be in there! You don't *have* to strain it if you're happy with the texture already. If you still want to, you can use a chux cloth. I get a mixing bowl, place a sieve above it, and then lie the muslin/chux on top. Make a few layers, then pour the yogurt on, cover with the overhang of the cloth, and strain until you've reached your preferred thickness. Just be careful not to make cream cheese