There are two ways to add a new producer:
From the Producers tab
Click on the Producer tab.
On the left-hand side, click Add Producer
Optionally assign an importer to a producer.
When a new Wine is created with this Producer and an Importer is specified here, then that Wine will also be made with this Importer.
By creating a new wine
Click on the Wines tab.
On the left click on New Wine.
On the next page, you can enter your new Producer name in the field.
Continue to create your new wine. Upon save, the Producer will be created.