It's very important, as you don't have excess yeast in suspension working actively to outcompete any bacteria, although the alcohol levels in wine are typically enough to keep most nasties at bay. I would really suggest being as sanitary as possible. Get an autosiphon for $15 and never look back.
I can't be arsed to keep up this list of what's in the fermenters, but hey, check out the cool brewery I own!
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