Moisture content is the total water in cannabis flower, expressed as a percentage of mass. It is what a moisture meter reads. Water activity (aw), by contrast, measures the fraction of that water available to microbes.

Why it matters

Two lots at the same moisture content can have very different water activity, and it's aw that determines microbial risk and shelf stability. Operators who chase a moisture-content number without aw discipline routinely over-dry to feel safe.

From the floor

Moisture content is fine as a throughput and handling metric. It's the wrong metric for microbial safety or cure-readiness.

Related field notes

• Don't drop the ball on the one-yard line