What Can We Mix With Wine To Control Acidity Without Reducing The Taste Much?

Hello :)
Great question, just a few suggestions of what I do:
A) - try adding 7-up, Sprite, Ginger Ale, something of that nature
b) - as someone said, Club soda is a great idea - throw in a few limes or lemons, depending on the wine, for a nice lil kick
c) - sometimes I'll mix wine with a vodka and cranberry drink, or maybe a screwdriver, makes for a great taste
d) - another great (and similar) idea is to mix wine, seltzer, ice cubes, lemon/lime, and a fruity (I prefer a dark fruity with a Shiraz or the like) Frutopia or Gatorade in a pitcher or punch bowl - also great for parties! It's been a big hit as a summer cooler...
Hope these help you! :)

Unfortunately anything you add takes away from the true nature of the wine. Older wines have less acid, and whites have less. I suggest if you are going to mix don't use citrus, that's more acid. Water, Club soda are okay but change flavor too much. I suggest going with more of a spritzer idea; 2 parts white wine, 1 part white grape juice or apple, 1 part 7-up, slice, generic lemon/lime soda etc. Mix and pour over ice. Refreshing and just mildly alcoholic... Nice on a hot day with cheese and fruit, but kinda a girls drink. Oh I almost forgot also you might try sparkling apple cider, or sparkling grape. I prefer something stronger like a nice Gin & Tonic with a squeeze of lime....mmmmm!

You can add club soda or water to your wine to get rid of this problem. Prefer white wine over the red one, because it causes less acidity.

Do not add anything to the wine. You neutralize the acid once it is in your stomach

7up with wine is a good wine cooler