Ice Cube Coffee

I've heard of this style for iced coffee before, I have a few questions if anyone knows more about it.

How long do the coffee ice cubes keep? Given that you keep them cold enough, do they ever turn overly bitter or loose flavor in the freezer?

How do you mix them to make a drink? Do you blend the coffee cubes into a shake/coffee-malt beverage, or add more liquid; coffee, milk or water?
I have done it in the past...not sure how long they kept...we used them so quickly! As to how you serve it....I used a rocks glass 2 oz of scotch and the coffee cubes! 8) or took hot coffee and poured it over the coffee cubes so's not to dilute the coffee!
coffee cubes

I ahev been making iced coffee cubes for about 3 years now- I usualy use a cube tray that has a cover to avoid picking up any of the freezer tastes/ odors.