I assume we’re talking about what to do if you’ve already opened the wine. Sure, if you don’t like a wine - if you’re able to taste it before you buy - then don’t buy it.
My experience is that there are a number of wines that suffer specifically from high alcohol and not necessarily from other problems. That’s one of the major reasons that some winemakers partly dealcoholize components of their wines - and you’d never know as a consumer unless they told you. Dilution may have a more negative impact than dealcoholization, but if I add 5% of a tartaric acid solution to a 16% ABV wine, it’ll bring the alcohol down to 15.2%, and I’ve had several otherwise nice wines that I’ve done this to.
I know people think this kind of thing is sacrilegious, but I don’t really understand why, except for ideas of purity or what have you. People add salt to their food. People add a splash of water to high-proof whiskey to help unmask aromas. Why not play around? I will say, I don’t think people should rush to do this, since wines change over time. I wouldn’t do this regularly, only if something otherwise nice is really being hampered by excessive alcohol - otherwise I’d be more inclined to let a wine open up and see where it goes.
Not ITB, but I do this more often than I’d like (thanks to Coravin and Repour). If Wine A is missing something, and Wine B has that something in excess, why wouldn’t you blend the two?
Have definitely made improvements, and occasionally turned a “meh” wine into a “wow” wine.
Also, for wines that are too high in ABV I mix in some non-alcoholic wine. Leitz makes a decent Pinot and Geisen makes a decent red blend for everything else. Yes, it changes the character somewhat but better than trying to smell/taste past that overbearing alcohol character.
Of course, this is something I only do for myself. I wouldn’t bring my “fixers” to a restaurant or wine-gathering.
Edit: By “decent” non-alcoholic wine, I mean not horrible. Most are pretty bad. Still haven’t found a white or rose that doesn’t taste like old grape juice.
Wines picked at very high sugar levels tend to be very concentrated because the grapes have lost some water as they (over) ripen, so in most cases of very high ABV wines I doubt that a little dilution would leave them lacking concentration. Of course, dropping an ice cube in a glass may result in a pretty significant dilution!
In California, it is legal to add water before fermentation (Ridge even lists water as an ingredient on some of its wines), and I understand that that is quite common.
But I also understand that the effect is quite different when it’s added before fermentation rather than to the finished wine. For example, fermentation slows at high alcohol levels because yeast start to die around 15% (and the mix of yeasts changes to those that can survive at higher alcohols), so pre-fermentation dilution may help sustain a complete fermentation with the desired yeasts.
But I’m not a winemaker. Larry may be able to explain this better.
