If your grandmother cooked as did mine (long time ago) she probably had her own little "secret ingredients" so you may find it difficult to find exactly the same taste...
I found this one but it has quite a few ingredients - I find the original recipes didn't have a lot of "fancy stuff" in them - just a few ingredients - good luck!
(maybe look up "traditional Grogg recipe"?
http://goscandinavia.about.com/od/re...loggrecipe.htm