After washing the collard greens, cut out the stems and ribs. Stack the greens then roll the greens, lengthwise. Cut slices from the entire roll at 1-inch intervals. You should now have lots of collard green strips.
In a large pot, cook the bacon on medium heat until crisp, turning once. Remove the bacon from the pot, leaving in the grease.
Add the garlic and cook while stirring for 30 seconds. Add the greens to the pot and cover with an inch of water. Chop the bacon and add it to the pot, along with the salt and vinegar.
Bring the pot to a boil then turn the heat down to low. Simmer uncovered for 1 1/2 hours or until the greens are slick and tender. Check on the pot occasionally and if the liquid gets too low, add more water. Taste the pot liquor when done and add more salt if desired.