Great-Grandma's Legendary Fudge vs. A Determined Daughter In Law

I've known my husband and his family since I was about 15 years old. One holiday season, thinking I'd bring the family a treat, I made a batch of the well-known "Never Fail Fudge", using marshmallows in the recipe. While the fudge disappeared by midday at the house of my then-boyfriend's family, his father informed me that fake fudge didn't hold a candle to his grandmother's Legendary Fudge.  I shrugged it off, but the topic would come up periodically through the years: Oh the deliciousness!  Oh the failed-yet-noble-attempts by his wife!



Finally, years later, when my husband and I finally tied the knot, I was presented with the legendary recipe, along with a phrase now emblazoned into my mind, "If you ever make it, I'll kill you." said his mother, handing it to me. Not one to back down from a challenge, and eager to prove myself in some way, I thought: Game On.

That first year of marriage, I gave the recipe a try. Immediately, I was confronted with something disconcerting: the recipe's ingredients didn't make any sense. I might be a first-time "real" fudge candy maker, but I immediately realized that the list of ingredients must be up for suspicion.  Making some quick comparisons to other otherwise similar fudge recipes (these are the "old-fashioned" types), I decided an additional type of sugar listed really should have been labeled "milk". "Okay, let's note that might make a difference!", I thought, feeling somewhat smug.

It was almost 8 years ago now, but the result from my first attempt was *not* fudge.  I tried again, fail.

Years have come and gone, and I've periodically tried again, sometimes getting closer and closer, but never with the consistency I picture as successful fudge (too hard).
I've not accepted this recipe at face value, done some extensive internet research, and have determined slight technique differences to be possible culprits against similar "old fashioned fudge" recipes. Armed with this knowledge, I tried once again this last weekend, after several years of leaving this mess for the birds!

I was stirring, stirring, feeling good about it, confident. Husband comes over and reads the directions, then states, "Keep mixing!" "I think it's done..." I said. "No, keep going!" he insisted. One of those things... no matter how well-meaning he was, I should have trusted my research.
Unfortunately it came out just as before, too stiff for my liking, despite the flavor being spot on.
SO! I have revisited the internet and tried to discern what I did wrong... and I am filled with confidence anew.  I may even give it a whirl after work tonight (yeah, right).

Stay tuned... if I successfully execute I will bring you the steps to my success and a recipe with confidence with which to wow your in-laws.  They are visiting this weekend, so boy wouldn't I love to present them with, oh, something I just "threw together" the other night.  ;-)

Update:  I tried again, and as before, I have the same struggle of the fudge being too thick to stir upon cooling to 110 degrees.  I found a great post from The Big Bake Theory that indicates I likely overcooked.  I'm going to get a new thermometer and see where that leads me, as everything seems in order except on that part.  No graininess and still tastes, great, but consistency is more like taffy when I go to stir, and cools to a rather solid candy that still melts in the mouth.