Why Does Honey Crystallize?

Many people are used to honey in its viscous liquid form. However, honey found in grocery stores has often been processed in ways that cause it to stay liquid for longer than it does naturally. Let's take a look at the science of honey crystallization.

All honeys will naturally crystallize over time, although acacia, sage, tupelo, and black locust honeys (all of these are honeys we don't find naturally in Ontario because these plants don't natively grow here) take an incredibly long time. All Ontario floral sources will crystallize quite readily, and even an unpasteurized Ontario honey will show signs of crystallization after several months or less.

In modern processing methods, mild to moderate heat levels are used for uncapping, extracting and bottling the honey. In most local Ontario apiaries, the heat used is mild and results in a high quality unpasteurized honey. Unpasteurized honey is not the same thing as raw honey, so let’s quickly look at some definitions.

What is Raw Honey?

Raw honey is defined by never being exposed to any human-made heat outside of the hive, or can also be defined as never being exposed to heat higher that 104°F (40°C), according to the Canadian Honey Council's CBISQT Producer Manual (2014 copy). 
I produce my raw honey using cold process extraction, which means there is no heat in my uncapping knife and no heated tanks involved when I am straining out bits of beeswax and bottling my honey.

What is Unpasteurized Honey?

Unpasteurized honey is warmed to temperatures ranging from 104°F (40°C) to as high as 110°F (43°C). Beyond 110°F, the quality and beneficial compounds in the honey begin to degrade, with nutrients and enzymes being denatured (changing protein structures due to high heat).

Adding some mild heat to a commercial extraction system increases the efficiency of the work (a LOT, based on my own experience cold-extracting versus seeing and working in my brother's commercial extraction process). Most local Ontario apiaries will use some heating options in their honey extraction systems. This results in a quality product that is able to be produced efficiently, and thus can be priced competitively.

In making my decision to cold-process extract, I am choosing a significantly more labour intensive method so that my honey can be 100% sure to have all of it's health benefits (pollen, enzymes, antioxidants) intact. I hope to find ways to make it faster in the future, but that will require additional space and equipment that I need to budget for. In the meantime, I am simply putting in the work!

What is Pasteurized Honey?

Any honey heating that reaches past 140°F (60°C) is considered pasteurization, destroying nutrients and enzymes. Most pasteurized honeys are heated to a range of 145°F (63°C) to 167°F (75°C), held for a specific time (I believe it might be 1-4 minutes) and then rapidly cooled. This kills yeasts and prevents fermentation (if the honey had too high a water content, more on that in another blog post) and severely delays crystallization. It does not kill botulism spores, which was it's original intent when introduced to the honey industry (more on this in another post too). Thus, honey pasteurization is really just a commercial process to create a consistently liquid product. Unfortunately, that product is ultimately not as healthful as a non-pasteurized honey. 

Most pasteurized honeys are also pumped through a filter, removing almost all traces of pollen and other tiny molecules that honey crystals like to attach to, which results in further delay of the crystallization process. And that brings us back to the point of this blog post: crystallization.

Honey Crystallization:

The majority of honeys will begin the process of crystallization as soon as they leave the 95°F (35°C) hive. Honey can also crystallize inside a hive if the bee cluster isn’t on top of it and it drops to 50°F (10°C) for a while.

How fast honey crystallizes involves a number of factors:

• floral source & how much glucose versus fructose the bees created
• how well strained or filtered the honey is
• storage temperature

Floral Source & Glucose vs. Fructose:

Nectar in a flower is mainly made up of sucrose and water, along with various minerals. Meanwhile, honey contains a variety of sugar molecules, including glucose, fructose, sucrose and maltose. During the process from nectar to honey, the bees’ stomach enzymes break down most of the sucrose in the nectar into glucose and fructose. About 70% of the final honey content is made up of glucose and fructose, while around 16 to 18% is left as water.

What does floral source have to do with it?

Different floral sources may result in differing ratios of glucose molecules to other sugar molecules, which is why there are honeys that take forever to crystallize as mentioned in the beginning of this post. Additionally, some honeys seem to consistently crystallize with a finer smoother texture than others. I particularly notice this with summer blossom honey, while a spring dandelion/wildflower honey tends towards a coarser textured crystal structure. This may be impacted by extraction processing, as I’ve noticed that my cold extracted and less heavily strained honeys tend to be smoother textured regardless, while honeys that I sometimes purchase from other apiarists seem to exhibit this pattern.

While all of the sugar molecules are the reason that the honey tastes sweet, it is the glucose that influences crystallization. Over time, the glucose molecules crystallize or separate out of the super-saturated solution (honey) that the bees have created, forming their own preferred crystal structure.

Straining or Filtering:

Once crystallization begins, the first crystals act as seed, creating more crystals and filling the whole container. Tiny molecules of pollen, propolis and wax can also serve as a building point for crystals to start from. This means that a lightly strained honey like my cold-extracted honey is going to have more of these fine particulates of pollen, propolis and wax which glucose molecules can adhere to. Typically, folks who are using heated commercial extraction systems are straining their honey through a finer sieve that takes out more of this particulate matter and this factor contributes less to the crystallization speed. A pasteurized honey that has been pumped through a filter will have little to no particulates for the glucose molecule to join.

Storage Temperature:

When honey drops towards 10°C it will crystallize much faster as that is an optimal temperature for the crystals to form. Honey stored between 20°C and 35°C will remain liquid for a longer timeframe, and frozen honey will not crystallize because the process cannot happen while it is frozen, although freezing an already crystallized jar will not reverse the process.

It is interesting to note that honey often crystallizes from the bottom up. This may be because of a lower temperature on the bottom of the jar or due to the crystals drifting to the bottom because they weigh more.

Now that you know the factors that contribute to honey crystallization, I’d like to also add that crystallized honey is still perfectly fine to eat! It has not gone bad or off, and you can revert it back to its liquid form, all that’s required is an application of some kind of heat.

Returning Crystallized Honey to Liquid Form

Ultimately, I would suggest using your raw honey in its crystallized state rather than trying to keep it liquid, but if you are specifically wanting to keep it raw and liquid here is how I would do it.

When you are de-crystallizing honey you must be careful not to overheat it. Overheating may burn it, degrade enzymes, and alter the flavour of the honey. Putting honey in the microwave is a no-no because the heat will not be uniformly spread across the honey and your chances of overheating are increased.

The best method to return a jar of honey to liquid at home is water immersion:

• Heat water to boiling with a tea kettle or saucepan.
• For the tea kettle method, place your jar into a bowl and pour the hot water in around it. Allow the jar to sit in the heat, stirring and repeating the process as needed to reach your desired level of liquidity.
• For the saucepan method, once the water is boiling turn off the burner, remove the pan from heat and place your jar directly into the water. Again, allow it to cool to room temperature and repeat the process if needed.
• A fully crystallized jar will need several repetitions of this process.

Another method is to use a crock pot on its lowest setting with water around your jar for a long, slow warming; however, this does carry a risk of overheating. A final option for a really crystallized jar is saucepan water immersion with a canning rack (or a layer of metal cookie cutters also does the trick) on the bottom to keep the jar of honey from overheating on the bottom. Then you can leave the pan on the burner and maintain the water at a hot temperature for a longer timeframe. Again, remember that you can still easily overheat the honey in this setup. If desired, you can use a candy thermometer to monitor the water temperature.

A good rule of thumb is that if it’s hotter than your hand can stand, the temperature is too high, but do take into account that you need the heat to transfer through the glass, which is why I’m not stressed about telling you to pour boiling water around the glass jar or immerse it in boiled water without allowing it to cool down – the glass will absorb the bulk of that initial heat blast.

Want to force crystallization or make creamed honey?

As discussed in the beginning, honeys will naturally crystallize over time, so you don’t have to perform any special steps to get a naturally crystallized honey. However, if you prefer the crystallized texture and want it fast, or if you want to make a creamy texture, here is how you can do it in a small batch at home:

• combine liquid honey with some crystallized honey
• maintain it at a low temperature around 55°F (10-12°C)
• stir the crystals in well and then stir regularly to help the honey fully crystallize quickly

A creamed honey is one that crystallizes very smoothly with a creamy texture.  While some honeys do this naturally, many apiaries manipulate the natural crystallization process to produce large quantities of creamed honey. We do this using the same process as above, but with a specifically selected source of starter honey or specialized equipment to cause the crystals to be so small they are creamy in texture. Thus, it usually works best to use a bit of professionally creamed honey as a “seed” to start your homemade creamed honey. This is because the smooth textured crystals will tend to transfer throughout the honey and cause the rest of the crystals to stay small too, so long as you stir it regularly.

If you have a stand mixer with a dough hook, you can try that out to stir it with less elbow grease required, but be careful of wearing out your motor if the honey is really thick.

Store your creaming honey at the temperature mentioned above, and stir it well every day so that it maintains a smooth texture. When the honey is creamed to the consistency you prefer, you can then store your honey at room temperature again and discontinue daily stirring. 

Usually it takes a few days to a week for honey to naturally crystallize in this manner, whether you perform regular stirring for a creamy texture or are looking for the more coarse natural texture. 

Hopefully this blog post has more than answered any questions you had about honey crystallization, but if not, do let me know in the comments or via my contact form. 

If you want to learn more about honey and botulism, honey water content, or why honey doesn't go bad, stay tuned for several more blog posts over the next couple of weeks!

References:
Brunning, A., The Chemistry of Honey.  Compound Interest, 2014. http://www.compoundchem.com/2014/08/21/chemistryofhoney/

Geiling, N., The Science Behind Honey’s Eternal Shelf Life. Smithsonian Magazine, August 22, 2013. Retrieved on February 5, 2016 from: http://www.smithsonianmag.com/science-nature/the-science-behind-honeys-eternal-shelf-life-1218690/?no-ist 

Honey. Wikipedia. Retrieved on February 5, 2016 from: https://en.wikipedia.org/wiki/Honey 

How to Use Honey. OBA. Retrieved on February 5, 2016 from: http://www.ontariohoney.ca/all-about-honey/how-to-use-honey

Why Does Honey Crystallize? Brookfield Farm Bees & Honey Blog, December 14, 2010. Retrieved on February 5, 2016 from: https://brookfieldfarmhoney.wordpress.com/2010/12/14/why-does-honey-crystallize/