27 CFR 4.71 – Standard wine containers
(a) A standard wine container shall be made, formed and filled to meet the following specifications:
(1) Design. It shall be so made and formed as not to mislead the purchaser. Wine containers shall be held (irrespective of the correctness of the net contents specified on the label) to be so made and formed as to mislead the purchaser if the actual capacity is substantially less than the apparent capacity upon visual examination under ordinary conditions of purchase or use; and
(2) Fill. It shall be so filled as to contain the quantity of wine specified in one of the standards of fill prescribed in § 4.72; and
(3) Headspace. It must be designed and filled so that the headspace, or empty space between the top of the wine and the top of the container, meets the following specifications:
(i) 187 mL or more. If the net contents stated on the label are 187 milliliters or more, the headspace must not exceed 6 percent of the container’s total capacity after closure.
(ii) Less than 187 mL. If the net contents stated on the label are less than 187 milliliters, except as described in (a)(3)(iii) of this section, the headspace must not exceed 10 percent of the container’s total capacity after closure.
(iii) Exception. Wine bottled in clear containers with the contents clearly visible, with a net content stated on the label of 100 milliliters or less, may have a headspace that does not exceed 30 percent of the container’s total capacity after closure.