21 CFR § 130.12 - General methods for water capacity and fill of containers.
For the purposes of regulations promulgated under section 401 of the act:
(a) The term general method for water capacity of containers means the following method:
(1) In the case of a container with lid attached by double seam, cut out the lid without removing or altering the height of the double seam.
(2) Wash, dry, and weigh the empty container.
(3) Fill the container with distilled water at 68 °F to 3/16 inch vertical distance below the top level of the container, and weigh the container thus filled.
(4) Subtract the weight found in paragraph (a)(2) of this section from the weight found in paragraph (a)(3) of this section. The difference shall be considered to be the weight of water required to fill the container.
(b) The term general method for fill of containers means the following method:
(1) In the case of a container with lid attached by double seam, cut out the lid without removing or altering the height of the double seam.
(2) Measure the vertical distance from the top level of the container to the top level of the food.
(3) Remove the food from the container; wash, dry, and weigh the container.
(4) Fill the container with water to 3/16 inch vertical distance below the top level of the container. Record the temperature of the water, weigh the container thus filled, and determine the weight of the water by subtracting the weight of the container found in paragraph (b)(3) of this section.
(5) Maintaining the water at the temperature recorded in paragraph (b)(4) of this section, draw off water from the container as filled in paragraph (b)(4) of this section to the level of the food found in paragraph (b)(2) of this section, weigh the container with remaining water, and determine the weight of the remaining water by subtracting the weight of the container found in paragraph (b)(3) of this section.
(6) Divide the weight of water found in paragraph (b)(5) of this section by the weight of water found in paragraph (b)(4) of this section, and multiply by 100. The result shall be considered to be the percent of the total capacity of the container occupied by the food.