I made chocolate ganache and left it at room temp thinking it would harden up so I could cover a cake with it. Many hours later it is still runny, if I put it in the fridge and it hardens up can I bring it back to room temp and cover my cake with it? Or will it eventually go runny again?
Thanks!

Yes! Put it in the fridge to harden, then heat it for a few seconds in the microwave-depending on how much ganache you have, try 10 to 30 seconds-then stir it until its spreadable. Just be sure you don't get it TOO warm or you'll be back in the same boat.

I actually did this earlier today. I forgot to make my ganache in advance, but it all turned out great! Happy to help!

If it's room temp and still runny, I wouldn't cover the cake with it. Melt some more chocolate and mix that in, heating the whole lot again if you get lumps,

Thank you both! It is at room temp and still a little runny after leaving it in the fridge last night. I will try adding some more melted chocolate. I don't know why it didn't work to start with, I followed the recipe exactly...

There are different proportions for pouring and spreading ganache - maybe you used a pouring recipe?

The recipe I use for ganache is 1 part cream to 2 parts chocolate. I haven't made the white chocolate ganache, but I know its a little different...I want to say its 1 part cream to 3 parts chocolate, but don't hold me to that...I'll have to look it up. The regular ganache has always worked like a dream for me though!

I think I did use a recipe for poured ganache as it was so runny! I added some more melted chocolate and its a little better but it should still be hard at room temp right?

IT is definitely spreadable but maybe once it is spread thin on a cake it will harden? I just hate to ruin an entire cake with it if it isn't the right consistency.

At room temp, it takes 24 hours for chocolate to set back up completely. If you just add more chocolate, you will mess up the ratios after it's all said and done. Fridge it.

I refrigerated it after adding more chocolate and it firmed up but now that it is at room temp again it is spreadable. If I want to put in on a cake under fondant will it be ok?

Spreadable is fine, runny is not. As you work the chocolate (while putting it on the cake) it will cause it to seize up some (not in a problematic way unless you work it and work it and work it) and get a bit firmer. You can also refrigerate the cake again after coating and before fondant to make a nice work surface.

Great thanks so much for the help. Next time I will just use the 2:1 ratio and save myself all this trouble