Do I need two filters to strain cold brew coffee? I have a Filtron cold brew system that uses both a paper filter and a wool filter to strain the coffee after it has brewed. However, in the last batch, I forgot to insert the wool filter! Is it okay to strain the coffee through the paper filter alone before drinking it, or is the wool filter doing something that the paper filter does not?
I make cold brew regularly using an ISI whipper, and simply filter through one paper filter in a Chemex set up.  So, I am sure you are just fine.  The wool filter appears to be the main filter in this system, with the paper filter in place simply to extend its life (see the FAQ on the website).  You probably want to go back to the wool filter, since this is the design of the product, but I am sure your result is drinkable.