Fudge not setting up-- any salvaging possible? Alternate uses?

It sounds like your fudge simply wasn't heated enough. Fudge is basically a superconcentrated syrup, and it sets when sugar dissolved in the water (from the butter and milk) comes out of solution as the mixture cools and forms crystals. Temperature is your proxy measurement for the concentration of sugar - if you don't hit the right temperature, the concentration will be off and your fudge won't set properly.

Here's a useful little article with some tips for fixing your fudge. Essentially, you want to cook the syrup right up to 237° to 239° F (that's 114° to 115° C) in order to get the proper concentration. I generally heat my syrup up to 235° F and let carry-over do the rest of the work. If it's overcooked (resulting in grainy fudge) or undercooked (resulting in poor setting) all you really need to do is add a bit of cream, reheat the fudge to the target temperature, and let it set again.

logophobe's answer is correct on how to fix this.

As for what you can do with it if you don't want to start over:

My favorite uses are as hot fudge topping or dissolve it in water or milk for luxurious hot chocolate.

I had an issue with my fudge coming out (after setting overnight) the same consistency as what you put over an ice cream sundae. Here's how I fixed it:

I added more sweetened condensed milk (that's all, nothing else)and microwaved it with the "syrup" I made that was supposed to be fudge. After the first 2 minutes I stirred it really well and stuck it back in for 2 more minutes. Stirred it again and stuck it in for 3 minutes. All on high.

After removing it that third time, I let it sit on the counter (not stirred) for 10 minutes to cool and settle. Then I started stirring. And stirring and stirring. And then I stirred some more.

I started out with liquid and the consistency from there went to that of frosting, then to cake batter. As I picked up the bowl it was in to get a better stir, I noticed the bottom of the bowl was still quite hot. I then had this brainstorm: I was using my middle sized mixing bowl so I thought, What if I put this middle sized bowl inside the larger bowl with some refrigerated water in it? Well...that was the ticket!

You can only put about 1 inch of water in the larger bowl or it will come up over the top of your bowl of fudge and mess that all up so do not put more than one inch of very cold water in that larger bowl. It made the consistency thicken much faster but beware it is kind of messy trying to hold the fudge bowl still when it wants to spin in the water. I had to refresh the water 5 times, about every 3-5 minutes. The key seems to be in cooling the fudge enough for it the thicken and it went much faster with this technique.

Please note that when I put the fudge bowl inside the larger bowl with the fresh cold water, I let it sit about a minute before I started stirring. The pyrex bowl I was using had retained a lot of heat and that's what was causing the fudge to not thicken so I was actually cooling the bowl off, not so much the fudge.

My cake batter consistency fudge quickly went to that of taffy and continued to thicken from there. It never got to cookie dough consistency but I really couldn't stir it much anymore at all so I poured it into a pan and it's now in the fridge.

Fudge that just won't set can be

• decadent ice cream topping
• frosting for brownies
• (depending on how rich it is / the consistency you got) put it in a bowl and call it pudding! Top with a dollop of unsweetened whipped cream.