Spare ribs cook in a Crock-Pot with moist heat for tender meat that you can cut with a fork. Crock-Pot ribs require little prep time, and do not heat up the house like oven-cooked ribs. Spare ribs have little meat around the bone, making it difficult to check the internal temperature. The ribs are at a safe temperature when the meat pulls away from the bone, at about 160 degrees Fahrenheit.
Mix balsamic vinegar, Worcestershire sauce, mustard, brown sugar, chili powder, salt and pepper in a small bowl. Set the sauce aside.
Cut the ribs into sections of three ribs with a sharp knife to speed the cooking time with more surface area on the meat.
Pour the olive oil into a large skillet and heat it on medium-high. Place the rib sections into the skillet and brown the meat for two minutes. Flip the ribs with tongs and brown the other side for an additional two minutes.
Take the ribs out of the skillet with the tongs and put one layer into the bottom of the Crock-Pot. Brush the ribs generously with the sauce. Repeat with each layer until all the ribs are in the pot. Pour any remaining sauce over top of the ribs.
Cover the Crock-Pot and turn it to the "High" setting. Cook the ribs for four hours, or until the meat falls off the bone.
Check the internal temperature in a thick area of one rib to verify it is 160 degrees Fahrenheit.
Remove the ribs to a platter. Make additional sauce to serve with the ribs.