Hi, I have a few questions about making cold brew out of a french press. I have made some batches, but none to well results. What bean to water ratio should I use? Should I put the coffee in a airtight container or let it be open? Should I put the coffee in a dark room temperature area or in the refrigerator? What is double straining/filtering? Should the container be big enough for the coffee and water have some breathing space or small to where its clumped together? How long do you recommend letting it brew for? Any other tips/facts I should know about concerning anything cold brew? Thanks!