These powders pull water out of the air

Supplement powders are unusually thirsty. Most of what goes wrong with them, from a set-solid tub to a dose that is quietly wrong, starts with water arriving from the air.

The defining property

Dry protein and supplement formulations are mainly hygroscopic: they absorb moisture from their environment. Which is why they are conventionally held in packaging that excludes humidity rather than merely contains the powder.

This is not an occasional problem in humid weather. It is the normal behavior of the material, happening continuously whenever it is open.

What moisture actually breaks

More than people expect. Moisture uptake wets the solids, and that affects stability, flow, compactibility, dosing accuracy and hardness.

Read that list again with the dosing problem in mind. A powder that has taken up moisture flows differently and packs differently, so the same scoop delivers a different mass. The moisture problem and the dosing problem are the same problem.

And the protection that dryness gives against microbial growth is a function of low water content: microorganisms cannot live without water, which is why a dry powder keeps for a year or two. Let water in and that protection goes with it.

Why the container is a specification

For a hygroscopic powder the moisture barrier is not a packaging preference, it is part of the product's stability case. A tub with a poor seal is a tub in which the product changes.

Which is why induction seals, foil-lined pouches and desiccants are standard here rather than premium, and why a packaging change is a reason to retest.

Controlling it

Blend and fill in the driest conditions you can arrange, and keep bulk material sealed rather than in open bins between uses. Minimize the time a batch is open.

Specify the closure and liner rather than accepting what ships. Consider a desiccant for the most hygroscopic formulas.

And tell the customer, on the label, to close it and keep it dry. It is the one part of the chain you do not control and the part where most of the exposure actually happens.

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