Understood, but again, I'm not talking about for the purpose of topping off to reduce head space. I was referring to purposely using a big enough carboy and small enough batch of home made wine for a full bottle or multiple bottles of commercial wine for the purpose of influencing your homemade wine to adopt the flavors from it. Sorry if there's a gap in communication, I think it's because I'm a rookie newbie and some of you are seasoned wine makers. I understand now that it would likely not add much flavor, if any noticeable flavor at all. I think the assumption from the seasoned wine makers thought I meant topping off while I was actually meaning flavor influence and/or blending, but as a poster above said, it's home made wine and we can really make it to our liking. Kind of an aha moment for me (I thought to myself "Duh!"). Sorry for the confusion on the question but I certainly appreciate all the comments, it's nice to see how active this forum is and I can soak up all the wine making knowledge.