Step 3: The brew.
Take your third cup and place it (Bottom down) on the center of the 6" diameter circle of cardboard. Take a pencil and draw the outline of the bottom. Your should have a circle the size of the bottom of the cup centered on the disc of cardboard. Cut out that center circle.
Test fit the bottom of the empty cup into the inner circle. You may have to trim it but the cup should slide in about 2" at least, but not too far.
Test fit it with the top of the cup. It should side on the rim of the empty cup with any obvious problem.
Now the brew.
Get your double cups with the grounds out of the fridge and remove the lid. Give it a last stir.
With one hand lift the inner cup from the outer cup, but always have the inner over the outer so the liquid that comes out falls into the outer. lift it high enough to quickly slide the cardboard between the two cups and insert the upper cup into the hole of the cardboard.
Rest the cardboard on the lip of the lower cup and let sit. I should take about 15 minutes for the upper cup to stop dripping.
Once the upper cup has stopped dripping remove it from the cardboard and place it inside the third cup you have had hanging around. Fill the cup with water again and replace the lid and return to the fridge for a second soak. ( this batch will be ready after work - a little weaker.)
Set aside the cardboard for later. You will get a lot of use from this.
Now you have about half to three quarters of a cup of black gold. A very high concentrate coffee.