Honey crystallisation

The crystallising of honey is a natural process that is likely to occur more quickly with raw honey when compared to the processed honey found in supermarkets, which has been extensively heated and filtered. Some supermarket honey also contains added water and sugar syrups that slow down the crystallisation. The crystallisation of honey has no effect on the honey apart from the change in colour and texture, and some people believe it helps preserve the flavour and quality of the honey.

Honey should not be stored in the refrigerator as this will diminish the quality of the honey. Crystallised raw honey is safe to eat, even after many years on the shelf. In general, honey will keep forever. However, no honey should be given to babies as there is a slight risk it may contain Clostridium botulinum spores, which could make babies very sick.

Why does honey crystallise?

It’s all about ratios. The two main sugars in honey are fructose and glucose. The amount of fructose and glucose in honey varies, but generally, the fructose ranges from 30- 44%, and glucose from 25- 40%. The balance of these two sugars affects the crystallisation of honey, and the relative percentage of each determines whether it crystallises rapidly or slowly.

During crystallization, glucose sugar which is white, separates from water and becomes crystals, while the fructose remains as a liquid. As the honey thickens, it becomes more viscous and lighter in colour.

Why does some raw honey crystallise faster than other honey?

A variety of reasons determine the rate of crystallisation in raw honey, the main one being the ratio of glucose and fructose in the floral nectar source. Honey from plants with a high fructose to glucose ratio like acacia (wattles), eucalyptus (gums) and leatherwood crystallise slowly and may stay liquid for years. Whereas, honey from vegetable and garden plants including lavender, daisies and dandelion, as well as the brassicas (eg. cabbage and broccoli), lemons, peas and clover have a low fructose to glucose ratio and crystallise quickly, sometimes in just a few days or weeks.

Also, raw honey contains small bits of wax, pollen grains and propolis which serve as nuclei accelerating the growth of glucose crystals.

Honey and heat

Raw honey is not heated in order to preserve its many health benefits. For example, the antioxidant and anti-inflammatory benefits provided by the phytonutrients in honey are diminished when the honey is heated above 40 degrees.

Air temperature will also affect the rate of crystallisation. The colder the weather, or storage area, the faster the honey will crystallise. Honey should be stored at room temperature in an air-tight container.

To return a jar of crystallised honey to liquid state, simply place the jar in a bowl of warm water (about 40ºC) until the crystals have dissolved. Don’t heat raw honey too much as this will destroy some of the beneficial enzymes it contains.