Tartrates in wine are both tasteless and harmless.
Tartrates, which are potassium bitartrate crystals, are sometimes found floating in white wine or sticking to the bottom of the cork. These crystals, which are the same as cream of tartar, are bits of natural tartaric acid that have precipitated out of the wine, usually because of a quick extreme drop in temperature. (As when you take a wine out of a warm car and plunger it into a bucket full of ice.) Winemakers often remove them before bottling, but don’t worry if you find them in a bottle of white wine. They are harmless and won’t affect the taste of your wine at all.