It clouded, separated or threw a sediment

Cold is the common trigger

Constituents soluble at room temperature come out below it, which is why a bottle stored somewhere cold clouds and often clears again when it warms. It is the same mechanism the oils property describes for olive oil.

Time does it too

Extracts continue to settle for weeks after they are made, so a product bottled bright can throw a fine sediment on a shelf. Letting an extract settle and decanting before bottling reduces it and does not eliminate it.

Glycerites are more prone to it

Glycerin holds less in solution than alcohol does, so a glycerite is more likely to cloud or separate and more likely to do it at ordinary temperatures. That is a property of the carrier choice.

Tell the buyer

A line saying that natural sediment is expected and to shake before use turns a return into a sign of a minimally processed product. In a category whose buyers often prefer less processing, that is a positive rather than a disclaimer.

When it is not cosmetic

Cloudiness in a product that was always clear, a change in smell, a film or anything that suggests growth is a different matter, and a low-alcohol or glycerin product is where that is plausible. Those are a formulation and preservation question rather than a settling one.

Filtering is a choice with consequences

Fine filtration gives a clearer, more stable-looking product and removes some of what was extracted. Deciding how far to filter is a product decision to make deliberately and record in the specification.

Photograph it before you replace it

A customer photograph distinguishes settling from growth in seconds and saves shipping a bottle back to find out. It also tells you whether the complaint is about a batch or about one bottle stored somewhere cold.

References