Raw honey contains all the pollen, enzymes and other micronutrients that are usually filtered out or destroyed by heat when honey is processed. Traditionally, honey is heated and filtered so that it will remain liquid much longer on the market shelves, but this process strips away many beneficial properties of honey.
Honey crystallizes over time - Honey is naturally acidic and low in moisture, making it inhospitable for bacteria. While converting nectar into honey, bees flap their wings to draw out excess moisture. Bees also have a special enzyme in their stomach that helps to break the nectar down into gluconic acid and hydrogen peroxide (the peroxide acts to further prevent the growth of bacteria and other organisms in the honey). Raw honey will crystalize more quickly due to the fact that it is unfiltered, but can be melted into liquid easily by submerging the jar in hot water.