I made this last night and they turned out really tough. Any suggestions on what I did wrong? Of course I didn't know for sure if I got the membrane completely off to start. When the recipe says to lay them cut side down in the DCB what exactly does that mean? Maybe we had the wrong type of ribs? I just know my husband tried to eat one then threw them in a pot of water to boil them until we went to bed to see if they would get tender.