Many people here are old hands at making Gordon's Formula, but there is surprisingly little about the topic on the internet for people new to the idea. For those of you new to the subject, Gordon's Formula is a paste food for fish, with a beef liver base. It was developed during a time when commercial foods were relatively expensive (and really they still can be), and especially if you are keeping a lot of fish. At the moment I don't have a lot of fish, but I think it's fun to make your own fish food.
This recipe has appeared in a number of publications. Here is the recipe as it appeared in the "Guppy Handbook," by C. W. Emmens, T. F. H. Publications, 1970:
1 pound of fresh beef liver
20 tablespoons of Pablum or Ceravim (Gerber or other brand Oatmeal baby cereal)
2 teaspoons of table salt
My wife has forbidden me from using our food processor for this, but since I knew I wanted to make another batch of this stuff I've keep my eye open for a cheap blender. As luck would have it we were in a Rite Aid yesterday and they had Toastmaster blenders on clearance for 75% off! So I got a blender for less than 7 bucks, which I can dedicate to my fish purposes.
I'm going to document my newest batch. I only vaguely used the specific proportions, as I prefer to go mostly by feel. I used a pound of beef liver that is already deveined. I highly recommend that route if you want to reduce processing. Otherwise you have to devein it and remove any fat or other material.
As a variation to the above formula, I heated a coffee cup full of water until it boiled in the microwave, then dissolved a packet of unflavored gelatin in it. I added that water to the blender with the liver. I blended the liver until it was liquified, then poured it through a strainer into a glass bowl. Liver liquifies really easily, so a blender works great. You'l find variations of the recipe that use beef heart, and for that I'd use a food processor. The reason I added gelatin this time is because in the past when I hadn;t, the fish tear into this stuff so aggressively that it sends a cloud of fine particles into the water which can foul the tank if you're not careful. This is a first for me using gelatin so we'll see if that helps.
You can try skipping the gelatin and just adding a couple of cups of water to your liver when you blend it. Once blended, add the salt and add enough baby cereal for the mixture to reach a thick, peanutbutter-like consistency. I don't measure, I just add it and stir it a bit at a time until it's right. As a variation for this batch, before adding the baby cereal I through in some old left over flake food. It adds a bit of nutrition. There are a lot of variations out there, with people adding blended carrots, peas, blanched spinach, etc. Feel free to experiment.
Usually I bake the mixture in the over, covered with foil, on 350 for about 30 minutes. This time a microwaved it for nine minutes on high in the glass bowl, stiring after 3 minutes and again after 6 minutes. Then I left it to cool. Once cool, I divided the mixture between three queart sipper backs, pressing the paste down so the air gets out as I zip it. Then I put the bags in the freezer.
I felt this time the mixture was a bit dry from the microwave, so I might bake it again next time, but overall it came out well. Here is a link
to a different forum when I first made the recipe, but I used chicken liver instead. I might try that again, because I liked the way it turned out and the chicken liver is less...pungent...than beef liver