How many bottles you will get
Updated
A planning number that is less obvious here than elsewhere, because a fermented batch loses volume in ways a blended one does not.
The arithmetic
Bottles equals batch volume minus losses, divided by fill volume.
Fill volume is the declared net quantity, not the bottle's nominal size, a 330 ml bottle filled to 330 ml has headspace above that, which is part of the container rather than part of the fill.
Losses
Residue in vessels, hoses and the filler, which is proportionally worse on small batches and is several percent.
Trub and sediment left behind when racking off a ferment or a fruit base.
Evaporation, during hot extraction or an open ferment, which for a long open fermentation is not trivial.
Foam and spillage at filling, which for a carbonated product is the largest single loss.
Samples: retains, laboratory samples and quality checks, which for a batch tested properly is a real number of bottles.
Ten percent is a reasonable starting assumption for a still product and fifteen for a carbonated one. Measure your own.
Worked example
A 40 liter batch, 12 percent losses, filled at 330 ml.
40 liters minus 12 percent is 35.2 liters, which is 35,200 ml.
35,200 divided by 330 is about 106 bottles.
Then subtract the retains: three cold and three warm leaves 100 to sell.
Working backwards
For 500 bottles at 330 ml you need 165 liters of product, which at 12 percent losses is about 188 liters of batch, which is several vessels rather than one.
And it is 500 bottles' worth of cold storage for however long they take to sell, which is usually the constraint the arithmetic reveals.