Explain the correct use. Here’s an example: I want to sell alcohol, such as wine. There is a draft wine, we buy it in containers of 5 liters. In the base unit I write 1 ml, in the transaction unit I write 5 liters and put a multiplier of 5000, right? Then in the recipe I’m writing portion is equal to one glass of for example 180 ml. Now another case, I only have a bottle of 0.75 liters and it is sold only as a whole. Can I write in the basic unit " 1 bottle “and in the recipe indicate the expenditure of” 1 bottle"? Will it be correct?
Any values can be used, for unit based products like the wine its allot easier as like you said 1 unit can be bottle and then by by single units or case or whatever.
Draft is not so a ml is simple to manage.
The recommendation for non packaged units is the smallest common dimoninator (remember fractions from school 
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ml is a small unit but easy to multiply out, if all served portions were round to say 10ml you could have used 10ml and a 180ml glass would be 18 units,- you could say 60ml units and say glass is 3x units.