Grinding active dry yeast finer?

Most bread recipes I've seen in books and online call for instant yeast over active dry since it can be added directly to the flour and doesn't need to be dissolved in water beforehand. I love this idea, but I have a big jar of active dry yeast in my freezer that I'm still widdling down before I go buy more yeast. Dissolving the granules in water is a real pain (especially when they're frozen since they really don't want to dissolve) so I was wondering: if the main difference between active dry and instant is that instant yeast is comprised of finer granules, can't I just grind up active dry yeast with a mortar and pestle to get the same result? I can't imagine that this would break up the cells or do any other harm to the yeast but I'm not sure.