The Good Beer Guide to Germany (2006) says;
"Like Bremen, Hamburg's brewing scene is dominated by one giant, with the odd brewpub thrown in for good measure"
Holsten brewery (owned by Carlsberg) in Altona.
Groninger Braukeller, Willy-Brand-Strasse 47, Hamburg-Messberg.
Hanseat, Zippelhaus 4, Hamburg-Messberg, (wheatbeer only).
Johan Albrecht, Adolphsbrucke 7, Hamburg-Messberg
(there are 6 Johan Albrecht brewpubs).