A lively exchange took place this week on Twitter, between some Chicago food critics and journalists. They weren't debating whether or not the soup was good, but how critics should talk about soup – or dessert – or restaurants –through social media. We turn to our own food contributor – David Hammond to give us a post by post. WBEZ food critic David Hammond contributes to the Chicago Reader and Time Out Chicago. He also moderates LTHForum.com, the Chicago-based culinary chat site.