You could look at the estimated median income in the postal code you are considering for your brew-pub.
You could look at NB liquor's reported sales volumes of beer (may or may not be available publically) to see which types of beer are the most popular.
You could get beer consumption data by province from Stats Canada
You could:
see what sorts of restaurants are in the area of your location and offer something slightly different, but not grossly out of place;
talk to people who have founded brew-pubs elsewhere
hire a market research firm to do a survey for you