Shrimp Broth

I collected two pint zip-lock baggies of shrimp shells from the many bags of frozen shrimp I buy. When I had a day off I defrosted the shells, ground them up in the food processor, and simmered them for 3 hours in a saucepan with 5 cups of water. I did not add herbs or vegetables. I wanted pure shrimp broth. When the simmer was done ,I strained then shells out in a colander, then strained them again through a funnel lined with a coffee filter. I used several coffee filters because of very persistent shell sediment. I was left with 4 cups of yellow-pink shrimp fragrant broth that I will use to cook rice or poach fish. I froze some of the broth in metal molds. Then I ran the molds under hot water for a moment to loosen them, then put them into freezer storage bags.