Chances are, it's happened to you. You're making a batch of fudge--but not the easy, add-marshmallow-cream-and-stir kind. This is legitimate fudge, old-fashioned fudge, grandma fudge, the kind that needs to be beaten in order to set up. You're following the instructions and stirring dutifully, the fudge is starting to thicken, and--bam! Suddenly you have a rock-hard lump in your saucepan where creamy fudge should be.
Or perhaps you have the opposite problem. You stir and stir and practically stir your little arm off, but your fudge never seems to thicken, and you're left with a gooey sauce that might be a good ice cream topping, but is definitely not going to pass as fudge.
Both of these scenarios--and many, many others--have happened to me in my years of fudge-making. I call it "when bad fudge happens to good people." Although fudge seems like a fairly simple candy, I think old-fashioned fudge is actually a very tricky thing to do properly! So much success depends on knowing when to stop beating, and this is something that is really best seen and understood through experience, not read from a recipe page. But we don't all have grandmothers to show us how to make old-fashioned fudge, so I have a few tips and tricks to get you through the process of making old-fashioned fudge. These tips work for any recipe that requires a sugar syrup to be cooked and then beaten until thick--if you'd like to read an example of this method, check out this Old-Fashioned Buttermilk Fudge recipe.
Check Your Candy Thermometer
The single biggest factor in fudge success is getting the sugar syrup cooked to the right temperature. If your syrup is overcooked, the fudge will be hard and grainy. If undercooked, it will be too soft and might not thicken at all. You can save yourself a lot of frustration and wasted ingredients by following these simple instructions to check your candy thermometer, and then, during the cooking, monitoring the candy closely to get it to the exact temperature specified by the recipe.
Beat the Fudge Until There is a Noticeable Change
I can't tell you how many emails I've gotten from people complaining about their fudge being thin and liquid. When I ask follow-up questions, they usually admit that they didn't beat their fudge for very long, or that it didn't really look or feel different after beating. This is a sure sign of under-beaten fudge! Specific recipes will give you exact guidelines, but as a general rule, the fudge should be nearly set when you're done beating it. It will have changed from a shiny, translucent liquid into a thick, matte, opaque fudge, with an extremely thick consistency. If it doesn't look almost set when you're scraping it into the pan, you haven't beaten it enough. And yes--this process can take a long time. It depends on the recipe and the size of the batch, but it can take anywhere from 5 to 25 minutes, so don't think a few quick stirs with the spoon will get the job done.
Stop Just Before It Sets
Look at the words I used above to describe when to stop beating fudge: "nearly set," "almost set." This is, for me, the hardest part of making fudge, because I always try to give it just a few more stirs, and then my fudge is suddenly thick and hard in the pan. Fudge is done when it has reached the matte, opaque look I mentioned, and your spoon leaves tracks through the fudge that are never covered up again. It's literally a matter of stopping before you give it the final stir or two, because you need a little fluidity in order to scrape the fudge into the pan and smooth it out. This is the step that takes the most practice.
A Spoonful of Hot Water Can Save the Day
If you don't quite succeed in the previous step, and find that your fudge has gotten too thick and can't be easily scraped into the pan, adding a spoonful of very hot water can help! Start with about a tablespoon of near-boiling water, and stir it into the fudge. The fudge should loosen up, and you can now pour it into the pan and smooth it out. If it loosens but is still too stiff, add a bit more water, trying to add as little as possible to be effective.
Wet Hands Help Too
I almost always use my (clean, washed) hands to pat the fudge smooth in the pan. If fudge is almost set, spreading it out with a spatula can leave drag marks and other imperfections on the top. Wet your hands lightly (or spray them with a thin layer of nonstick cooking spray) and press and pat the fudge smooth. The water or oil helps your hands glide over the fudge and gives the top a seamless look. Voila--perfect fudge!