Typically 2 or 3 a day.......half liters mind you. Weekends........double that. Triple it for BBQ, or friends over. This Saturday two old friends of mine are in town.........we'll sit around a nice big fire in my back yard and drink beer all night on Saturday.......typically we kill 3 cases in these marathon sessions.
I cannot keep up with it brewing. Every other batch I'll brew a light grain bill pale ale, usually with some corn or rice added, that I can ferment for a week and bottle for 2 weeks......makes an excellent quick, easy, and cheap session beer that's still better tasting than 90% of the stuff on the shelf at Safeway.
Even with brewing 3 or 4 5 gallon batches a month, I still end up supplementing with a case of BMC (actually, usually Michelob Amberbock).