Buttermilk Fudge not setting My grandma used to make buttermilk fudge for us every year for Christmas. I have tried and tried to make it and it never sets up. It tastes great if you want to eat it with a spoon. 

The recipe is

2 c   sugar 
2 c   buttermilk   
1/4 c butter  
1/3 c dark karo
1 tsp soda  
1 tsp vanilla 
1 c   nuts



  Cook till forms a medium soft ball. First cool a while and add vanilla and nuts. Beat by hand. 


I remember grandma always saying something about the shine. Oh why didn't I pay more attention?! What am I doing wrong?
I would bet that the "something" your grandma said about shine was "beat it until it's not shiny anymore."  The likely reasons that your fudge isn't setting are that you're either not heating it hot enough to begin with, not waiting long enough before you start beating, or you're not beating it until it loses its shine.  

Here's how I'd re-write your recipe's instructions to make them a bit more detailed.

Version 1 (you don't own a candy thermometer):
Heat the first 5 ingredients until medium soft ball stage.
Remove from heat and cool without disturbance for about 10-15 minutes. 
Add vanilla and nuts beat until the candy begins to lose its shine.
When it is beginning to thicken and becomes opaque, pour/scrape it into a prepared pan.

Version 2 (you own a candy thermometer):
Heat the first 5 ingredients until 240 F.
Remove from heat and cool without disturbance until candy reaches 140 F.
Add vanilla and nuts beat until the candy begins to lose its shine.
When it is beginning to thicken and becomes opaque, pour/scrape it into a prepared pan.