Some of the grapes we make wine with have a high amount of tartaric acid in them. When these wines get chilled, crystals can form. They are completely harmless and tasteless, so if you do see it in your wine, don’t worry! The ‘fancy’ name for them is wine diamonds! We have a process here where we chill the wine before bottling but it doesn’t always do the trick.
Here are some pictures of what the tartaric acid might look like