It depends what beer you are getting. I have been buying some decent locally brewed IPAs and they have 8% alcohol.
"As I am a Canada Border Service Officer I'm always here to help clear up any questions you might have. Just PM me and I'll be happy to get back to you quickly with correct information.
YES he may bring beer into Canada (or liquor if you prefer) without paying duty of any kind as long as it's within the allowed limits (1 case/bottle/1.5 ltr of wine) and if he's 18 and going into Quebec it's also ok. I hope this helps."
^^I found that on a forum and this is on the bc boarder and customs site. looks like we will be packing a lot of beer.
"Visitors aged 19 years or over may bring in 50 cigars, 200 cigarettes and 200g (7 oz.) of manufactured tobacco. The alcoholic beverage allowance permits the import of 1.14 litres (40 oz) of spirits or wine, or 24 x 355 ml (12 oz) bottles/cans of beer or ale, providing it is to be used for personal consumption. If you bring in more than these quantities, you will have to pay federal duties and provincial fees and taxes when you enter Canada."
^^that was from the bc boarder crossing site so it looks chill.