With stock tracking on, WithWine counts how many bottles of a wine you have at each stock location, and reduces the count as you sell. Stock tracking is set for each product.
Why stock tracking starts off
Enable Stock Tracking? starts unticked on every new product. If stock tracking were on and you hadn't entered any stock yet, the wine would show as out of stock and might not appear on your website. Keeping track of stock is also extra work, so you choose which products to track.
Turn on stock tracking for a new wine
Go to Settings > Products > Bottles and click + Add Bottle, then + Add New Wine. (See How to add a wine (bottle product).)
Click Stock to open the section.
Tick Enable Stock Tracking?. A list of your stock locations appears.
In Initial Stock, enter how many bottles you have at each stock location.
Click Save.
Turn on stock tracking for an existing wine
Go to Settings > Products > Bottles.
Click the wine's name.
Click Stock to open the section.
Tick Enable Stock Tracking? and click Save.
Add your stock with Stock Movement. See How to adjust or transfer stock for a wine.
What happens next
The Total Stock column on Settings > Products > Bottles shows the wine's stock. Products without stock tracking show Not Tracked.
What happens when stock reaches zero depends on the stock location's out of stock setting. See What's the difference between Back order and Dont sell?.