O'Neill drinking beer.
- "I find it a refreshing substitute for... food."
- ―Jack O'Neill
Beer is an alcoholic drink widely used on Earth. Members of SG-1 and the Atlantis expedition drink beer mainly for celebratory reasons. Teal'c, on the other hand, doesn't drink beer or any other forms of alcohol, as it could have adverse effects for his symbiote. (SG1: "Fire and Water", "Lost City, Part 2")
Colonel Jack O'Neill used beer as a "secret ingredient" for his barbeques, as he pours beer onto the grill with his steaks and other forms of meat. (SG1: "Citizen Joe", "Threads") He also, at one point switched brands. In 2000, he was drinking Budweiser, and later switched to Guinness in 2004 and then to Fat Tire . (SG1: "Shades of Grey", "Lost City, Part 1") In at least one episode O'Neill bought two packages of Heineken. (SG1: "Full Alert")
There also appears to be a bar (either officially or unofficially) on Atlantis. Lt. Colonel John Sheppard offered to buy Dr. Rodney McKay a beer to celebrate his engagement to Katie Brown (or to drown out his sorrows if she said no) and McKay once lost a bet to Dr. Jennifer Keller owing her a beer. (SGA: "Quarantine", "Trio")
While trapped under the rubble of a collapsed building, in order to confirm the identity of the people digging him out, Sheppard asked them what their favorite beer is; Duff Beer or Oprah Ale. When they answered Duff, he knew it was Michael Kenmore's Hybrids as both beers are fictional. (SGA: "Search and Rescue")