The 'controlled' spirits are gin, rum, vodka and whisky, and these must be served in either a 25ml or 35ml volume. The licensed premises must only use one or the other of these, and state clearly on a notice (prominently displayed) which size measures are used in those premises to inform customers. The premises may use optics attached to the bottles which automatically measure and dispense the right quantity, and it will state the measure used on the device. Alternatively they may pour straight from the bottle into 'thimble measures' to measure out the correct quantity, this method requires much greater care to ensure it is poured to the brim without spillage.
Note that cocktails involving mixtures of many ingredients may not need to be measured out in either of these ways.
By telephone: 01628 683802
By fax: 01628 683560
By email: trading.standards@rbwm.gov.uk
By post: Customer Service Centre, RBWM, Town Hall, St Ives Road, Maidenhead, Berks SL6 1RF