I always use tinned raspberries in a trifle but as I have some frozen ones thought I would use them but am a bit concerned they might be a bit sharp even though they will be in raspberry jelly. Has anyone else used frozen ones?
I use frozen raspberries with no extra sugar to serve with things like icecream or rich dessert cakes. I think they'd be fine in a trifle. You might want to sugar them a little overnight to draw our some of the juices to make them less wet (you can do this as they thaw). The juice can be used to make the jelly.
I always use frozen raspberries in a trifle. They have a better flavour than the tinned ones and are not so horribly sweet. If you can get fresh ones look out. They look better but they rarely have much taste at this time of year.