One of the neat things about making your own wines is you can change the way they are made however you want. If you want to substitute ingredients, have at it. The recipes are all only suggestions. Youdon't have to follow them to a T. When and if you change them, make sure you keep good notes so you can make it again if you like it. If you rely on your memory, I hope your memory is really a lot better than mine. Most retrys are months or maybe years later and little thing tend to get forgotten. Good luck with it, Arne.
And to answer your question, sure you can. Mite change the outcome a bit, but you can substitute. Personally, I would probably substitute. A frient of mine uses raisins and I can usually tell when they are added. There is a taste from them, but that is just me. Nobody else seems to notice. A.