This is the only way to go! You know exactly what's in the stock instead of using mystery products. Whenever I make a shrimp dish, I save the shells and add them to a zip-lock plastic bag and freeze. Because I am cooking for two, I keep adding to the bag until I've accumulated enough to make stock. I do the same with the scraps and trimmings from vegetables. (Don't save blemished parts.) By the way, onion skins add a rich golden brown color to stocks. Hungry for some seafood chowder?
This is great stuff. I never thought of cooking the shells and scraps before putting the water in. Thank you so much for sharing, this is definately worth the effort.