If you think an exchange is iffy then get two gift certificates for him. One is for his time to come to your location. It’s his time, and if you were him you would probably appreciate getting something for your time. Get a second one for the cost + tax of the bottle in the store plus a little more. Be as nice as possible (as long as he is also). Before you get to the bottle in question give him the tour of the place (if he wants to), let him see the work that goes into each bottle, and do all the tastings he wants. This will build sympathy and should reduce any negative reviews he posts.
Scenario 1: Bottle is fine, but customer doesn’t like the taste
Once you’re done with the tour you check the bottle. If it’s fine then give him the “thanks for your time” gift cert. Try to explain as nicely as possible that your product is as it supposed to be, but unfortunately it’s not his style. You could also recommend other versions of your products if he likes them better.
Scenario 2: Bottle is fine, go overboard with customer service
Same as above but give him both gift certs just as way to push him to not be overly negative in his review if he does any.
Scenario 3: Bottle is bad
Give him both certs, tell him it unfortunately does happen.
Scenario 4: Just give him $$$
Buy one bigger gift certificate and give it to him when he shows up. Don’t bother with the bottle until after he leaves. Do the tour tasting etc. Just be uber nice. Kind of like #2, but it removes any possibility of a confrontation.
You will not be able to do this for everyone that doesn’t like your product. But if you treat him well hopefully he will tell his friends that you were very nice and maybe win over some other new customers. This may be a way of getting something positive out of a not so great situation.