Before putting ingredients in pan, butter the sides of pan or spray with Pam. When your fudge starts to boil, cover pan with lid for a couple of minutes and then remove. I also wash sugar from the spoon you first stirred with. I have made fudge for many years and it is never grainy. I hope this helps.
By Faye Moore from White, GA
I too was taught to "not stir" my fudge after it begins to boil. For some reason, it makes it grainy. I've never put a lid on it but I assume this is a good way to keep one from stirring. :) I'll try using a lid to see if it makes a difference. Thanks for the tip!
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I make fudge for a living. What I do is melt cooking chocolate first, then take it off the stove and pour in the can of condensed milk. Don't panic if it starts to thicken too much, just put it back over the heat and beat it as fast as you can with a wooden spoon.
The best way I've found to prevent fudge from turning gritty is to add 1/2 teaspoon cream of tartar for every 2.5 pounds of sugar used. Cream of tartar actually inhibits the sugar recrystallization process.
When making fudge, add 1/4 cup of clear Karo syrup to the ingredients. This stabilizes the fudge and it will not be gritty or chewy.