Heat a large skillet over medium-high heat. Add the beef, onion, bell pepper, celery and garlic to the pan, breaking up the meat as it cooks.
When the meat is cooked through, drain any excess grease. Transfer the meat and vegetables to slow cooker. Add the remaining ingredients and stir well.
Cover and cook on low for 6 to 7 hours. When mixture is finished cooking stir and taste. Add more vinegar, sugar, salt or pepper if needed. Serve the meat mixture spooned on to the buns or baked russet or sweet potato.
To freeze: After cooking the meat mixture and draining the grease, allow to cool. Place in gallon sized freezer bag with remaining sloppy joe ingredients. Remove as much air as possible, seal and label before freezing. To serve: Place contents of bag in slow cooker after thawing. Cover and cook on low for 6-7 hours.