Is the country of origin for a beer always the same as the brewers country of origin? I am creating a craft beer application which will contains a lot of information about beers. 

Now when modeling the data I am contemplating whether a beer itself should have a country, city and other address information, or whether this data should come from the brewery which owns the beer.

Can anyone come up with a valid reason why for example the country of origin from a beer would differ from that of the owning brewery's country of origin?

I ask this because a lot of time when you look at open source beer databases and projects you will see a country of origin when looking at a single beer but they are probably fetching it from the brewery that owns the beer.
It is not that common, but brewers may open subsidiaries. 

In 2016, Stone Brewing Co. from US opened a new plant in Germany (I suspect they wanted to expand in the European market). Where would your application locate those beers? (Plant was recently sold to Scottish Brewdog).

I suggest you locate beers where they are brewed.