Brown Sugar Trick

Ok, I think I am on to something.
I had some ROCK HARD brown sugar in my cupboard that I did not want to throw out. I also have those jars that sit on your counter, one for flour, one for sugar, and one for brown sugar. So, I put the ROCK HARD brown sugar into it's proper container and put the lid on. I had more than could fit and I didn't want to put it back in the bag, so I put the overflow into the white sugar container with the white sugar.
A few days later, I opened the white sugar container, having forgotten about the brown sugar transplant. To my amazement, the brown sugar in this container was super soft! Just like straight from the store. I opened the brown sugar container only to find that is was still ROCK HARD. I wanted to test my theory, so I put some more ROCK HARD brown sugar in with the white sugar. I checked it a few days later and sure enough, it was super soft!
I have come to the conclusion that if you put ROCK HARD brown sugar in a container with white sugar for a couple of days it will turn super soft (very scientific, I know). But, if you have some ROCK HARD brown sugar, try this out and let me know if it works for you.
Oh yeah, my only idea as to how this works is that the brown sugar soaks up the moisture from the white sugar, but I'm no Doctor :)