Wait, you actually posted an honest bad review of your friend's wine. I figured you'd just tell him in private. That takes some serious guts, especially knowing he'll probably see it. Was it that terrible, or just not your style?
Been in that spot before with a buddy's new business. If you lie and say you like it, you're setting them up to fail. Better they hear it from a friend who wants them to succeed than from ten customers who just won't come back. It was pretty rough stuff, tasted like grape juice mixed with vinegar. He asked for real feedback, so I gave it.