I'm looking into brewing a Baltic Porter sometime this winter. I notice alot of recipes use Vienna, Munich and Pilsen malt.
Would it no longer be the same style if I sub-ed Munich for the Vienna?
not sure I follow you - are you saying can you sub Munich in and just do Munich and Pils as your base malts?
Sure. Switching out Munich and Vienna in this style isn't a deal breaker - the flavor will certainly change a bit, but its still well within guidelines.
In fact, I don't think I've seen many recipes that include Vienna come to think of it (and I would notice being that I really dig vienna).
I'm making a BP next weekend - using Munich I & II and Pils along with chocolate and Carafa II.