There are test kits @ your LHBS that help you test acidity. Usually around 10$ (american) and the shop owner should be able to show you how to use one.
If your newest batch ends up being too acidic for your taste, you could blend it with something less tart. Or, you could use Potassium Bicarbonate to drop out some of the Tartaric acid. Finally, there is the tried and true method of waiting. Time will reduce the acid somewhat.
Hope this helps!