In Norway, as far as I know, the sale of all alcohol is nationalized. I'm going to visit my friend there, and his parents want to send him a bottle (He is from Slovakia, same as myself). Is it legal to bring home-brewed alcohol with me to Norway?
The import laws cited on the the page of Norway's Toll Office do not distinguish between the manner the alcohol has been created (because that would likely be rather difficult); only by the strength. You're allowed for free (see the link for how much you have to pay if you need to import larger quantities):
Note that you need to be over 18 to import alcohol at all, and over 20 to import hard (>22%) liquor.
The same information in pictures: