Crystallization is a natural attribute of pure, raw, unfiltered honey. It does not affect its quality and nutritional value, only its external features, such as color and texture. A crystallized honey is, by no means, spoiled, adulterated, diluted or no longer fit for consumption.

The process of crystallization actually preserves honey’s flavor and quality characteristics.
Crystallization is a natural, spontaneous and uncontrolled process, with the exception of spruce honey, by which honey turns from a liquid to semi-solid state with granular composition. Specifically, glucose sugar molecules separate from water and align into orderly arrangements, known as crystals. Factors that determine crystallization are: nectar source collected by the bees (the composition ratio of glucose to fructose), humidity (water composition), presence of pollen grains, pieces of beeswax, seed crystals, propolis and storage temperature. Generally, the higher the glucose and the lower the water content of honey, the faster the crystallization. Raw and unfiltered honey crystallizes faster, as the minute particles it contains serve as nuclei for crystallization.
Cold temperatures are ideal for crystal formation and accelerate the process of crystallization. Honey crystallization is more rapid around 10-18ᵒC (50-64ᵒF). Refrigerator temperatures accelerate the process of crystallization.
Raw honeys crystallize differently depending on their composition. If honey crystallizes uniformly through the jar, it can remain in this form for years without losing any of its nutritional value. If honey, however, partially crystallizes, it may turn soar very soon. In that case, you need to re-liquefy crystallized honey.
Hot Water Bath (Bain Marie): Crystallized honey can be brought back to liquid consistency by gently heating it in a hot water bath (Bain Marie), without losing any of its nutritional value. Heating should be applied indirectly, not by direct flame to the container. It is best to heat it at 35-40ᵒC (104ᵒF) to avoid overheating. Overheating honey for any period of time destroys its taste, aroma and nutrients.
Heat a saucepan filled with enough water to reach the level of honey in the jar to 35-40ᵒC (95-104ᵒF). Then, remove it from the heat or turn off the heat. Take the lid off of the honey jar and immerse the jar in the water. Let it stand out for 20-30 minutes. The heat will slowly dissolve the glucose crystals, becoming liquid again. Stir occasionally to even the heat throughout the honey, until the granules have dissolved. Repeat process, if needed. Remove the jar from the water bath, when honey becomes liquid again.