Each mix has a Count stock by setting: Number of bottles (the default) or Number of mixes. This setting can be confusing, so check it before you add stock to a mix.
Number of bottles (default)
The mix's stock is counted in bottles.
To make mixes available, enter the total number of bottles. For example, to have 2 twelve-bottle mixes available, enter 24.
Reports show how many bottles you sold through mixes. For example, selling one 3-bottle mix, one 6-bottle mix and one 12-bottle mix shows as 21 bottles.
Number of mixes
The mix's stock is counted in whole mixes.
To have 2 mixes available, enter 2, whatever size they are.
Reports show how many mixes you sold. The same three sales show as 3 mixes.
Why Number of bottles is the default
For most businesses, knowing how many bottles were sold through mixes is more useful for reporting than knowing how many mixes were sold.
Change the setting
Go to Settings > Products > Mixes and click the mix's name.
In Count stock by, choose Number of bottles or Number of mixes.
Click Save.
Check the mix's stock matches the new setting, and adjust it if needed.
Bottles in the mix
This setting only affects the mix's own stock. If the mix has mix items, each bottle in the mix is still counted separately in its own stock.