Jørn Dahl-Stamnes wrote "the flavour of raspberry is so strong, that it is
often
used to give other wines an extra flavour, or bouquet. A pure raspberry wine
imho is very nice when made of 1-1.5 kg per 4.5 l wine at the most. It can
be
given more body with grape concentrate as the total fruit content is quite
low.
Everybody decides for themselves. I also add 2 kg black currant and 2 kg
raisins to a 30 liter batch. Make the wine much better than pure raspberry
wine."

I've never made a raspberry wine but I judged 9 black raspberry wines this
last weekend at the Greater Kansas City Cellarmaster's wine contest. Quite
a few of these wines contained a portion of grape juice/wine in the mix.
IMO
the only wines that actually smelled like raspberries, tasted like
raspberries,
and had the tartness that I associate with raspberries, were the pure
raspberry
versions. Most all of the wines were nicely made and very drinkable. But
if
it's raspberry you're after I think it's better to be a purest.

Bill Frazier
Olathe, Kansas