Filling by weight

Filling looks like the trivial step and it is where three separate regulatory obligations meet: what the label declares, how full the container looks, and what you sealed into it.

Weight, not volume

The declaration on the principal display panel is a net quantity of contents, and where that is by weight it is a net weight. So the jar has to contain that mass, not that scoop.

Volumetric filling of a low bulk density material is inherently imprecise, and the imprecision moves whenever the grind changes or the source container settles. A scale under the jar removes the entire class of problem and costs less than a case of closures.

Where the headspace comes from

Fill to weight and the headspace is whatever it is, which for leaf material can look like a lot. That empty space has a regulatory name: slack-fill is the difference between the container's actual capacity and the volume of product in it, and nonfunctional slack-fill in a container the consumer cannot see into is misleading.

Functional slack-fill explicitly covers unavoidable settling and the practical inability to reduce package size further, both of which genuinely apply to spice. The defense is that the space does something, not that the weight was correct.

Which means the container choice and the fill are one decision, not two.

Fill in a dry room

At the moment of filling the product is spread thin and fully open to the room, and a second later it is sealed. Whatever the air was, a portion of it is now inside every jar for the life of the product.

Below 55 percent relative humidity if you can manage it. If the room will not cooperate, fill early rather than late and do not fill on a wet day because the schedule says so.

A workable bench setup

Scale, tared jar, funnel sized to the grind, a soft brush, and a check-weigh of a sample from every batch written down. Set the target a little above the declared weight, because the distribution has two tails and only the low one is a compliance problem.

References