You can now make your own vessel status icons (like the original Chilling & Carbonated) to have full control over the different statuses that you want to use and how they should show. Head over to Settings > Production settings > Vessel statuses to configure your own options. They can be toggled on/off in from the main page for a batch or by going to the vessel's page. Status toggles will be logged automatically into the "Analysis" tab on the batch too!

This was another community-requested and planned feature, so thank you to everyone involved. See the original request at Increasing the number of the vessel/tank status icons (Chilling and Carbonated).