Ultimate Fudge Sauce

I'm thinking of making this for Christmas presents. Will this keep out of the refrigerator? How long? 

Thanks for any advice!

(I haven't made this yet, but there's no way to ask a question without leaving a review that I see...)

Oh my goodness...yummy! I took the advice of the reviewer below and stirred in the chocolate after taking the pan off the heat. I did not have unsalted butter, so dropped the 1/8 teaspoon the recipe called for. Also, I used bittersweet chocolate instead of unsweet...helped that it was an excellent chocolate. I doubled the recipe, since this is for a gift...would definately make again!

It sounds like the first reviewer broke her chocolate. It's like burning it. You don't want the liquid to be too hot so I removed mine from the stove before mixing in the chocolate. Turned out great!!

I'm not sure what I did wrong BUT this came out grainy to the point of being non-palatable! What a disappointment and I believe that I followed the directions exactly as written.