I've put off making fish stock for a long long time. Fish doesn't top the charts of my favorite flavors in the least. Usually only the mildest flavored fish can be found in my dishes. So making something really fishy? That looks at me? And not knowing a good source for fish heads... Well, it was a challenge I could happily ignore. I dutifully saved the recipe in my file (which is oh so basic!) and thought nothing more, until I met someone who works for a fish shop - and can get me free fish heads.
Then the fish heads sat in my freezer. They would look at me as I dug for my beef bones and ground pork, but it wasn't until I learned that even beef stock isn't allowed on lenten fast days, that I finally took the plunge. And guess what, fish stock isn't so bad. It tastes quite good - the flavor is different, but I enjoyed it. Only downside is that the house does smell like fish for the 18hours that you are simmering it. Not a bad smell, if you like fish, but not quite what I hope to walk into when I come home. Chicken stock or beef stock simmering is such an inviting smell... but fish? Well, it was worth it anyway. Once done, I drained the stock, picked out mushy stuff and threw it into my soup. The heads disintegrate while they cook, so I only recognized little white balls as they eyes, hurray!
As for the recipe, I refer you to The Healthy Home Economist. The text of her recipe is below:
3 quarts of filtered water
2 lbs of fish heads and bones (fish heads alone will suffice)*
1/4 cup raw, organic apple cider vinegar
Himalayan or Celtic sea salt to taste
*Do not use oily fish such as salmon for fish stock or you will stink up the whole house! Only use non-oily fish such as sole, turbot, rockfish or, my favorite, snapper. I've also used grouper in a pinch, but the stock does not taste nearly as good.
Place water and fish heads/bones in a 4 quart stockpot. Stir in vinegar while bringing the water to a gentle boil. As the water first begins to boil, skim off any foam that rises to the surface. It is important to remove this foam as this is impurities and off flavors. Reduce heat to a simmer for at least 4 hours and no more than 24 hours. Cool and then strain into containers for refrigeration. Freeze what you will not use in one week.
**and just a PS - I'm not 100% for sure that the heads I got from my fish monger were non-oily - which may account for the entire house smelling of fish. Either that, or it is because I have a very small house. Either way, the stock turned out wonderful.