How Long Will Honey Last?
Man has been collecting honey for thousands of years. Samples of it were found in Egyptian tombs, and ancient cave paintings depict our ancestors hunting for honey.
The exceptional quality of honey, in that it doesn’t have an expiry date, makes it indispensable in every household. Who doesn’t use honey when baking or even when having a sore throat or a skin rash to treat?
The question is — does honey really last forever, and why? Can it ever go bad? The simple answer is, “No.” But, why doesn’t it degrade in time? Let’s take a look.
From Plant Nectar to Honey
It all starts with bees collecting nectar from plants and storing it inside their honey stomach. This is not their normal stomach, but a special compartment called honeycomb. It contains various enzymes coming from the bees’ glands. These enzymes have a very important role in honey production, even after the bees deliver the nectar into their hives.
Nectar from the flowers consists mainly of sugar but also contains traces of amino acids, proteins and lipids. They’re all mixed in a water solution. Sugar is the most dominant ingredient, and it’s present mostly in the form of sucrose.
Besides sugar, water is the second main component of nectar and, later on, honey. The low water content in honey is the key to its durability. For enough water to evaporate, bees need first to transform the sugar structure of the sweet solution.
Bees Work Hard to Decompose the Sugar
The role of bees’ enzymes is to break down the sucrose into simpler molecules. Sucrose is a disaccharide and consists of two different monosaccharides – glucose and fructose. In sucrose, molecules of glucose and fructose are interlinked. Enzymes break these molecules down into a mixture, where glucose and fructose react with water separately and differently.
All this is done during the bees’ flight back to the hive. There, the other bees take over. They repeat the process for the majority of sucrose to get broken down into glucose and fructose. In the end, only a small amount of sucrose (1–5 percent) stays present in honey.
It’s only then that fructose can dissolve in the water, while glucose starts forming crystals. The bees’ next job is to minimize the content of water in the rest of the liquid solution.
Less Water, More Longevity
The nectar is stored in the honeycomb and contains up to 70 percent of water at first. After bees are done with the sugar breakdown, they need to minimize the content of water in the nectar. A low amount of water is what makes honey so stable and durable.
Bees in the hive encourage the evaporation of water by fanning the honeycomb with their wings. During this process, water content will drop from 70 percent to a maximum of 20 percent.
An environment with this low amount of moisture doesn’t support bacteria development. Instead, it dehydrates them. This means honey’s key for resisting spoiling is its low water activity.
Honey’s Low Water Activity
We measure water activity on a scale of 0 to 1. Most bacteria need an environment with a water activity of 0.75 and more to survive and develop. However, honey water activity on this scale is 0.6 or even lower. This doesn’t make honey bacteria friendly, and therefore it’s resistant to spoiling.
Too Much Water Leads to Fermentation
For its durability to last, honey must be stored properly. Its containers or jars should be well-sealed. If not, honey can absorb too much moisture from the air. The chances aren’t high of this occurring, but this can lead to honey fermentation. You can recognize fermented honey mostly by its bad smell.
Fermentation is caused by sugar-tolerant yeast, if the environment has enough moisture. This can happen even after the amount of water in the solution drops to 20 percent or less. In rare cases, it can occur after the crystallization of honey.
How Is Fermentation Prevented?
Commercial honey is usually pasteurized or creamed. Pasteurization means heating the honey to at least 150 degrees Fahrenheit for half an hour and then cooling it off rapidly. During this process, yeast spores are destroyed. There is no guarantee pasteurized honey won’t start to crystallize again, though.
Creaming the honey with a method called the Dyce process is another solution. It speeds up the crystallization at a low temperature, which makes honey thicker, but smooth afterward. Honey still has its crystal structure, but it’s so delicate, you can’t really spot it with your naked eye.
Creamy honey seems to be more stable, but only at room temperature. If the temperature is higher, honey may become unstable. Its texture will become partly hard and partly liquid – and therefore dangerous for the yeast to develop again.
Can Crystallization Make the Honey Go Bad?
Crystallization of honey is a natural, self-regulating process and it doesn’t affect honey’s quality. However, after crystallization, one or more layers of extremely liquid honey can appear next to the crystallized part.
For honey to last unlimitedly, it needs to keep its water levels below 17 percent. If the liquid part of honey contains more than 17 percent of water, the solution becomes yeast friendly. It may cause the existing spores of yeast to grow, and that leads to honey fermentation.
One way to prevent this is by slowing down the crystallization process. You can purchase honey, which has already been processed and isn’t in its raw, crystallizing state anymore. Moreover, you can also control honey’s crystallization at home.
How Can You Decrystallize Honey?
At regular room temperature — between 50 and 68 degrees Fahrenheit — honey has the most ideal conditions for crystallization. If needed, you can regulate honey’s crystallization in several ways.
If you want it to crystallize slower, store your honey higher than room temperature — greater than 68 degrees Fahrenheit.
Cooler temperatures — below 50 degrees Fahrenheit — speeds up the crystallization process, so putting honey in the fridge might not be wise if you’re trying to decrystallize it.
If you want to get just a small amount of honey into a liquid state again, use a warm water bath. Put a certain amount of honey in a small jar bathing in warm water for no more than 15 minutes. Alternatively, you can always microwave the honey.
Though crystallization occurs, it’s not very likely your honey will go bad. The most important thing is to keep it well-sealed and at a proper temperature. This way, it should last indefinitely. It’ll also keep all its beneficial enzymes that are destroyed during overheating (pasteurization).
What Else Helps Honey to Last Forever?
Any water solution has a certain pH value, which can be more acidic (pH value below 7) or alkaline (pH value above 7). While pure water has a neutral pH of around 7, honey’s pH is around 4 and makes honey more acidic. However, most of the bacteria can only survive in an environment with a more neutral pH.
Honey contains several acids, such as formic acid, citric acid and gluconic acid. Gluconic acid is the main player here and is produced during the decomposition of sugar. This process is helped along by the bees’ special enzymes.
During this process, a certain amount of hydrogen peroxide is also produced. This substance is a great addition to honey’s antibacterial properties. That’s why different cultures have been using honey to disinfect and protect superficial skin wounds for ages.
No Expiry Date Needed?
Food products are usually labeled with expiration dates. However, honey — if stored well — should remain edible indefinitely. Beekeepers will rarely put an expiration date stamp on their jars. It may not last forever, but it’ll stay edible for as long as you have it. Its structure and color may change during time due to crystallization, but that doesn’t mean the honey has gone bad. Rather, it can provide us with an idea of how long that jar of honey has been resting on the shelves.
The truth is, there’s very little chance for the processed honey to go bad in time. Stored well, it shouldn’t contain enough water or moisture for the yeast to thrive there. The same goes for raw honey with a clear crystal structure.