When parchment coffee beans reach around 12% moisture, they are usually bagged in burlap or water-resistant bags and stored until milling. During storage, the beans are at risk of taking on more water so it’s important to keep them in a dry, cool, and low-light environment and to keep monitoring moisture levels.

Select samples from three different areas of each bag (not all from the top or the bottom), and check that they are representative. That is, consider whether they appear uniform and free from defects. Then use the cone method to check the percentage of moisture. If the parchment measures above 12% humidity, consider drying it further on beds, patios, or in a mechanical dryer.

So far we have only discussed parchment coffee, but green coffee beans (that is, beans with the papery parchment skin removed in hulling) more easily absorb moisture from the air. So there’s a greater risk of green coffee taking on moisture during storage. For this reason, it’s even more important to keep green coffee beans in a dry, temperature-controlled location.