Before that, they will be set to unique as this would be the most logical system and given barcodes are typically a retail thing and Samba being primarily Hospitality orientated this senario would not have been taken in to consideration.
Anyway, the suggestion…
Guest Beer Product with portions for the seasonal beers.
Will show on receipts ok: 1 x Guest Beer.Seasonal Name
Then set the guest beer product to have the auto portion selection ask question setup;
