I love Coinstar! I was excited to see that they partnered with Shaw's a few months ago. I just went on their site and saw that you can redeem your change for a Stop & Shop gift card now too!
How it works? Bring your change to a Coinstar kiosk. Have the machine count your money. If you opt to get a gift card, there is NO FEE. If you opt for cash, there is a 7% charge or something like that.
So go to Stop & Shop with your big old jar of change. Cash it in for a Stop & Shop gift card. Then you don't have to worry about the grocery bill charge on your credit card!