Why Honey Crystallizes & How to Decrystallize Honey

Ever wanted to pour some honey out of a jar, only to find it hardened up completely? It no longer flows and the only way to get some out is with a spoon.

If so, you’re not alone! This is a very common phenomenon and it certainly doesn’t mean your honey has turned bad. Don’t throw it out. Your honey has simply crystallized. It will still taste and behave like honey, be it a little thicker. If you need it to flow again, you can decrystallize the honey, by heating it up gently. In a microwave, it can be done in a matter of minutes.

Why honey crystallizes

First things first, let’s have a look at why honey turns solid over time. It’s all because of the sugars. Honey contains a lot of sugar. The most prevalent sugars in honey are fructose and glucose and there’s almost always a little more fructose than glucose. Honey also contains some other sugars such as sucrose, maltose, and galactose but they only make up a few percent. In total, over 80% of honey is made up of sugars. The rest is mostly water.

As long as all these sugars dissolve in the available water, honey is liquid. Even though sugars dissolve well in water, honey contains very high concentrations of sugar. If there’s too much sugar for the amount of available water, the sugar cannot remain dissolved. It will crystallize. It doesn’t just happen in honey, but can often be a problem when making candy also.

Crystallized honey will be slightly lighter in color. This is because the sugar crystals are white in color. They reflect light in a different way. It is also a lot firmer and thicker and no longer flows. It is not uncommon for some of the honey to crystallize, whereas the other part remains liquid. And even though you may think something is wrong: crystallization is actually a sign of good unadulterated honey! That said, not every good honey will crystallize. It depends mostly on its composition.

Ever eaten or made maple cream? That’s the crystallized version of maple syrup and the mechanism behind it is actually quite similar to that of crystallized honey!

More glucose increases the chances of crystallized honey

Not every sugar dissolves as well in water as others. You can dissolve four times the amount of fructose in water as you can glucose. It’s why, when honey crystallizes, it’s generally just the glucose sugars that will do so. Therefore, honey varieties with a higher glucose/fructose ratio crystallize faster.

Which is influenced by the type of nectar collected

Honey is a natural product. Bees make honey from the nectar they collect in their surroundings. They’ll use whatever nectar is available around them. Interestingly, the type of nectar they use to make honey influences the types of sugar present in the honey. As such, it impacts the tendency to crystallize. For instance, honey made from bees living close to raspberries crystallizes more rapidly than honey made by bees living close to cranberries!

How to decrystallize honey

Luckily, you can easily reverse the crystallization of sugars to make honey liquid again. You can decrystallize it by redissolving the sugars into the water. Since the solubility of sugars in water increases at higher temperatures, you do so by heating the honey. If you’re not a beekeeper and don’t have dedicated equipment for this, there are roughly two ways to do so.

1. Heat honey in a water bath

The solubility of sugars in water is temperature dependent. That is, when water is warmer you can dissolve more sugars in that same amount of water. It’s a crucial concept when making many types of candy. In honey you don’t even need very high temperatures to dissolve all the sugars. At about 40°C (104°F) all the sugars will redissolve. It is why you can decrystallize honey by placing the (glass) jar in some warm water. Simply stir regularly and the honey will slowly warm up and turn liquid again. Dissolving sugars take time, so it will not be an instant process.

2. GENTLY microwave the honey

Depending on the packaging material used, you can microwave honey, but, you have to be careful. First of all, most plastic packaging does not do well in a microwave. Therefore it might be wise to transfer the honey to a microwave-proof plastic or glass container. Secondly, honey easily overheats in the microwave.

Remember, to decrystallize honey it only needs to get about 40°C (104°F). So it only needs a gentle heat. A high heat can actually have a negative impact on the quality of the honey. The flavor may get affected and other components such as enzymes within the honey will break down. As such, when using a microwave, don’t use the maximum wattage. Instead, use a moderate to low wattage (360-600W) and heat for 10-20s maximum at a time, stirring in between to even out the heat. You’ll find that the crystals will disappear rather quickly. Depending on the size of your container you should see quite a big impact within 2 minutes for sure.

When making honeycomb, a type of candy, you do heat honey to very high temperatures. This will change the properties and flavor of honey.

How to prevent the crystallization of honey

Crystallization can’t always be fully prevented. Some types of honey are simply too vulnerable to crystallization. However, there are several ways to slow down crystallization, either during processing or during storage.

Stirring can induce crystallization

You may have noticed that your honey seems to remain liquid as long as it remains unopened. However, once you’ve opened it and taken some out, crystallization seems to happen rather quickly. This is not an illusion. By stirring, or agitating the liquid honey you’re helping the sugars to start forming crystals, or to grow existing crystals. So, don’t open several pots of honey at once, keep them closed until you need them if you want to reduce the chances of crystallization.

Filtering & heating honey delays crystallization

Energetically speaking, it’s very hard for that very first crystal to form in honey. However, once some crystals have been formed, the rest follows quite quickly. The first crystal forms more easily if there’s a place for it to grow on. This can be a bit of beeswax or other small particles within the honey such as some pollen. By filtering honey manufacturers get rid of any pieces, reducing the chances of crystallization.

Also, many manufacturers may heat the honey before packaging. Once heated, it is no longer raw honey though. By heating honey you’re dissolving all the sugars. As a result, these honeys don’t contain any ‘seed crystals’ to start with, so it will take long for them to start to crystallize. Nevertheless, they may still crystallize.

Whereas slight heating won’t damage or change the honey, higher temperatures will do so. However, high temperatures do kill off micro organisms that could otherwise cause spoilage of the honey. As such, there’s a trade off between stable, uncrystallized honey, and slightly less stable crystallized honey when it comes to using heat.

Infrared, ultrasound, or freezing may be the future

Crystallization of honey can be quite problematic for manufacturers. They can no longer pump or transfer the honey easily. It is why it’s been researched quite extensively and several newer process technologies are being investigated to slow down or prevent crystallization. One of those is infrared (IR heating). Others are investigating the use of treatment at very low temperatures (-40°C/°F) or the use of ultrasound.

Refrigeration slows it down

Crystallization of honey proceeds fastest at 10-15°C (50-59°F). In the fridge, it’s slowed down. At these low temperatures the viscosity of honey increases. This makes it harder for the sugar molecules to move around and find each other to form a crystal. At higher temperatures crystallization slows down as well because the solubility of sugars in the water increases, so they won’t be as tempted to start forming crystals.

References

Amariei, Sonia & Norocel, Liliana & Laura, Scripca. (2020). An innovative method for preventing honey crystallization. Innovative Food Science & Emerging Technologies. 66. 102481. 10.1016/j.ifset.2020.102481. link

Bhesh Bhandari , Bruce D’Arcy & Camilla Kelly (1999) Rheology and
crystallization kinetics of honey: Present status, International Journal of Food Properties, 2:3,
217-226, DOI: 10.1080/10942919909524606 link

Khalil Hamdan, Crystallization of honey, link – provides table on varying crystallization rates of different types of honey

Krishnan, Reshma & Mohammed, Thasniya & Kumar, Gopika & S H, Arunima. (2021). Honey crystallization: Mechanism, evaluation and application. 10. 222-231. 10.22271/tpi.2021.v10.i5Sd.6213. link

USDA, Food Data Central, Honey, FDC ID: 169640, link