Spread it on the kitchen table to air dry. Spread the product on paper in a dry, well ventilated shed. Weigh the dried product. Divide the end weight by the starting weight, then multiply by 100. This gives you a rough percentage dry weight.
Some producers claim their product protects crops from soil pathogens.
Evidence of disease control is usually based on greenhouse pot tests, using high rates of compost on plants other than fruit trees. The disease control often involves pathogens that are not specific to common orchard problems. We should stay skeptical on these disease control claims until we see better work done on the subject. So far, my compost trials show no economically significant control of replant disease. Claims of improved soil moisture holding capacity are weakly supported by research.