Honey Can Last for Years, But Does It Go Bad? How Should Honey Be Stored?
According to Livescience, there are at least 300 types of honey known today, produced by over 20,000 species of honeybees.
The Quality of Honey Depends on Many Factors
“The composition of honey depends on the type of honeybee,” stated Kantha Shelke, a food scientist at Johns Hopkins University (USA).
There are at least 300 types of honey known today, produced by over 20,000 species of honeybees – (Image: Shutterstock).
After collecting nectar from various flowers, bees convert sucrose – a complex mixture of glucose and fructose – into simple sugars with high concentrations.
Although honey is primarily sugar, it also contains over a dozen other components such as enzymes, minerals, vitamins, and organic acids. Honey also includes flavonoid and phenolic compounds, known for their anti-inflammatory and antioxidant properties.
The diverse chemical compounds produced by honeybees during honey creation make this natural sweetener unsuitable for microorganisms that typically spoil food.
The high sugar content of honey gives it hygroscopic properties, meaning it can attract moisture from the surrounding environment, even absorbing water from microbial cells nearby. Honey also has a low water activity level, making it difficult for microorganisms to thrive.
Once the bees transform nectar into simple sugars, they regurgitate the sweet liquid and pass it to other bees in the hive. When nectar is in the bee’s stomach, glucose oxidase breaks down glucose into gluconic acid and hydrogen peroxide. As the bees finally store the digested nectar in the hive, water gradually evaporates, turning this sweet liquid into a thick consistency.
The presence of gluconic acid, along with acetic acid, formic acid, and citric acid, makes honey even more acidic than coffee. This pH range is lower than what most microorganisms can tolerate. Additionally, the hydrogen peroxide in honey can prevent bacteria from forming a slimy layer known as biofilm that often adheres to surfaces.
All these chemical compounds inhibit microorganisms from decomposing honey.
Honey Changes Over Time
While honey remains safe to consume for long periods, it does change over time.
“The components of honey undergo changes due to crystallization, fermentation, oxidation, and thermal effects. These changes also depend on whether the honey is light or dark and on the source, or different seasonal regions, and the plants that the bees pollinate,” Shelke explained.
“Some of these changes affect nutritional and sensory properties, including the form of honey.”
Honey will also change over time.
When heated or stored for extended periods, honey may undergo the Maillard reaction, a chemical reaction that caramelizes sugars and turns them brown.
As sugars lose water, they can produce a potentially harmful compound called 5-hydroxymethylfurfural (HMF). HMF is also found in many other food products, including breakfast cereals, dried fruits, and milk.
The effects of daily HMF consumption are not yet fully understood. Some studies suggest that HMF may promote cancer, while others indicate that this compound may help prevent allergic reactions.
The Codex Alimentarius standards, an international food safety benchmark, have set an HMF limit in honey products at 40mg/kg. However, this limit varies depending on the type of honey.
For example, sunflower honey may reach the HMF limit of 40mg/kg after being stored correctly for 18 months, while acacia honey can take about 5 years.
Heating leads to HMF production, but cooling causes honey to crystallize. As honey cools, its sugar content becomes saturated and unable to remain in solution. This can also happen when moisture escapes from honey during storage, causing sugars to form crystals, according to Shelke.
Avoid Giving Honey to Infants
According to a study, the sensory and chemical properties of honey are best preserved at a temperature of 24 degrees Celsius, or around room temperature.
Given these variables, “the processing and packaging can significantly affect the shelf life of honey,” – Shelke stated – “Pure honey can last ‘forever’ if minimally processed and stored in a sealed container.”
Similarly, sterilized honey can last for several years. However, due to the lack of certain enzymes and antibacterial compounds, honey can spoil if not properly sealed or stored.
Notably, honey should be avoided for infants, as spores from the Clostridium botulinum bacteria can contaminate honey. These spores can withstand sterilization temperatures. They are generally harmless to adults but can cause poisoning and death in infants.
