If you have a particular barrel that you need to take out of a barrel group, you can use the Break Barrel operation to achieve this. This will then allow you track that barrel separately to the other barrels when recording jobs against that wine.
You can access this from Operation > Break Barrels.
Enter your batch code in the Product field and your list of barrels will be populated below. You can then click a barrel and select Break to move them out of the barrel group. You have the option to break out multiple barrels and put them in to a separate group if required.