pasteThe Evolution of Paste Foods 
By Charles Drew (H&DAS)




Probably the first paste food was developed by Dr. Myron Gordon, an American 
geneticist who studied hereditary cancer in fishes. He worked mainly with 
swordtails and platies and so his formulation was blended towards livebearers. 
The formula he used was basically beef liver, pablum, shrimp and spinach. 
"Gordon's formula" was all the rage amongst hobbyists when it was first 
published in the late forties or early fifties - which was about the time when I 
started in the hobby. I remember grinding beef liver and canned shrimp in an old 
hand-cranked meat grinder. Then you cooked a bunch of spinach and ground it up 
too, making everything just as fine as you could. Next you stirred it all 
together in a large bowl, adding a cup or two of pablum. After it was well mixed 
it was packed in small jars and placed in a pan of water on the stove and 
brought to a boil for half an hour. It was removed when the food looked cooked. 
It was then allowed to cool a bit before the lids were put on. It was then 
stored in the refrigerator. 
I used this formulation until the late sixties but then one day I was introduced 
to beef heart by Heli Kasza of Kitchener and I soon started on the beef heart 
formula. I trimmed the heart of fat and skin and ground it before running it 
through a blender. Also blended and added was cooked spinach or pablum. When 
well mixed it was frozen in flat plastic bags placed on a cookie sheet in the 
freezer. To feed it all you did was break off a piece and throw it into the fish 
tank. What a shortcut from the old "cook everything" method! 
This remained my basic formula, which may have varied a little from time to 
time, almost until the nineties. During that time I traded in my old blender for 
a more powerful food processor. Then lo and behold came the Discus craze. All 
the world's experts were raving about turkey heart. Soon all of us "turkey" fish 
breeders followed suit. Now turkey heart is not necessarily better than beef 
heart but in Germany, where the idea originated, it was probably the cheapest 
meat available. I soon found that I could buy it on the Kitchener market at a 
reasonable price and so I proceeded to switch to a turkey heart formula. The 
hearts did not have to be skinned; there was only some fat and a few arteries to 
trim out. The only other change was the use of agar rather than gelatin in the 
water you have to add in order to mix everything in the food processor. Agar has 
to be boiled in water in order to dissolve it. Why agar? Unlike gelatin, it 
won't dissolve in a ninety degree discus tank! 
Everything went well for a year or two. Then I started having trouble with 
angels as well as a few other fish. The fry would hatch, bloat, and die in a few 
days instead of becoming free-swimming on the seventh day. I tried different 
medications in the hatching water with no results. I blamed it on our city water 
which was as good a guess as any, until I decided it was a bacterium coming 
through from the parents. Treating the parents with an anti-bacterial medicine 
was the answer but the problem kept coming back. Where did the bacteria come 
from? I believe it came from the uncooked turkey heart. Which brings up the 
subject of to cook or not to cook. 
Cooking destroys bacteria in meat but it also destroys some vitamins. I find it 
toughens the meat and it is unnatural for fish to eat cooked food. I have since 
switched back to beef heart and no longer have the bacteria problem, which more 
or less confirms my suspicions. 
My present, 1999, formula is as follows. I start by cooking a bag of spinach. I 
leave enough water with it to make it blend fine in the food processor. Four 
beef hearts are cleaned of fat, skin and veins. It's then cubed and put in the 
food processor to chop and blend into a fine paste. You must add some water to 
do this. I dissolve a tablespoon of gelatin in two cups of hot water. Several of 
these "two cup cups" are usually needed. The gelatin binds blood and fine 
particles together. I also add two pounds of Alaskan pollock, a mild and 
inexpensive fish. A few multi-vitamin tabs are added and everything is mixed 
together in a very large bowl. Then, to make sure it's fine enough I run it all 
through the food processor one more time. I then pour it into metal cake pans to 
be frozen. A little water on the bottom of the pan after it's frozen will free 
it so that you can put it on a board and chop it into easy to handle blocks. I 
use a heavy, stiff-backed knife and a hammer. You could also use muffin tins. 
As you might imagine, there is no exact formula. Some people claim spinach 
contains something that destroys vitamins. I have also used Romaine lettuce, 
Swiss Chard or beet tops from the garden. Instead of fish I've used shrimp, 
squid or canned tuna. Some Discus breeders even put in pears or bananas and one 
even kept quiet for years about putting in a few cloves of garlic. But beef 
heart is the base. What you add to formulate the food to suit the needs of the 
type of fish you raise, is up to you. But just remember that you "gotta have 
heart".