Winegrowers Supplies  -  Bottle Filling

The correct 'fill height' for a bottle is embossed on the glass base, for example '63 mm @ 75 cl'. This means it should contain 75 cl when the bottom of the meniscus of the contents is 63 mm below the top of the bottle; usually this is at 15 C but to confirm this the bottle manufacturers specification sheet should be referred to.
Legally the EU permits a variance of up to 2 cl per bottle in the volume of the contents, but it is wise to try to fill as accurately as possible, not to under fill, as the volume changes with temperature; shrinking as temperature decreases.
Also one should not over fill or Customs & Excise will be concerned about Duty payment.
It is very important to print the 'e' mark on the label of every bottle, for example 75 cle, as this means that the average fill level of all the bottles is 75 cl, instead of every bottle having to be 75 cl (+/- 2 cl).

UK Trading Standards require the bottler to use a 'template' during bottling, regularly placing it over bottle tops in order to view/check the fill height against the template marking. It is not acceptable to use a ruler or tape measure!
Theoretically the bottle supplier should provide a template for the bottle, but I have never managed to obtain one. I made a template from a 120 mm x 120 mm square sheet of marine-grade plywood, cutting out a suitable recess in the centre of one side, about 90 mm high and 60 mm wide, to accomodate the bottle neck. I then drew a fine line across (in ink) at the appropriate fill level for the bottle (e.g. 63 mm) and wrote the height against the line. Ideally a separate template should be made for each different bottle fill height used.

UK Trading Standards would like bottlers to have their template officially authenticated/stamped, and be charged for the service, but this is not necessary as there is sufficient tolerance in the legal limits for fill volume.
For example, if a 75 cl bottle has an internal neck diameter of 21 mm at the correct fill height then the tolerance would be within +/- 5.774 mm [2000 (3.14159 x 10.5 x 10.5)] from the fill height.
In practice the bottle manufacturing tolerance could be perhaps +/- 2.5% (= 1.875 cl); this tolerance needs to be found out and taken into account.