Why doesn't honey go bad?
The short answer
Honey can last forever because of the ingenuity of bees. The nectar-to-honey process causes honey to fend off bacteria and microbes thanks to honey's low water content, built-in natural preservatives, and low pH acidity.
The long answer
Have you ever heard that honey doesn't go bad? It's true. More than once, pots of preserved โ3,000+ year old honeyโ have been found tucked away in tombs as an afterlife treat for the dead.
So what exactly is honey and what about it makes it last indefinitely?
What is honey and why do bees make it?
I had to start my research here because I quickly realized I had no idea what honey truly was. Understanding the process helps make sense why it's so long-lasting. If this is old news to you (or you're just a busy bee with no time for extra words), skip down to the next section.
Bees make honey as a way to preserve nectar for when flowers aren't in bloom. If they didn't go through a honey-making process, the nectar would ferment in the hive.
Here's a quick look at how bees turn nectar into honey:
A bee gathers nectar from flowers and stores it in her stomach. Special enzymes start to break the nectar down into simple sugars.
Once back at the hive, the bee passes the nectar mouth-to-mouth to a house bee. This further breaks down the sugars and starts to reduce the nectar's water content.
The nectar is placed in a honeycomb cell and is then fanned by bees' wings to evaporate more water.
Once the water content is below 20%, the bees seal up the cell with wax.
๐ Bee fact #1: A single bee will produce 1/12 of a teaspoon of honey in her lifetime.
๐ Bee fact #2: Yes, "her" - all worker bees are female. Only a handful of males are around with the sole purpose of mating with the queen bee. Then they die.
Why can honey last forever?
Here are three reasons why honey can last forever:
Reason #1: Honey has a low water content.
Honey is sugar central, and sugars are hygroscopic. This means it absorbs and draws moisture from the surrounding area and creates an inhospitable place for bacteria and microbes โ they simply can't survive in a dry environment.
Reason #2: Honey has natural preservatives.
Inside bees' stomachs is an enzyme called glucose oxidase. As bees regurgitate nectar to make honey, this enzyme breaks the nectar down into two by-products: gluconic acid and hydrogen peroxide. Hydrogen peroxide acts as a barrier to microbial invaders, keeping the honey pure and protected.
Reason #3: Honey is extremely acidic.
This same stomach enzyme process that produces hydrogen peroxide also leads to the creation of gluconic acid, which gives honey a naturally low pH between 3-4.5. This acidity is another line of defense, as most bacteria and microbes can't survive in this type of environment.
But... keep a lid on it.
While honey is impressively long-lasting, it isn't invincible. If honey gets too much moisture, like from an unsealed container in a humid environment, it can spoil. So, the key to honey's immortality? Keep it sealed and keep it dry.
๐ง Bonus brain points
If honey doesn't go bad, why is it sold with an expiration date?
Those dates on honey jars aren't really about food safety. Instead, they guide stores on when to bring in fresher stock. Honey may darken or crystallize over time, but it's still perfectly safe to eat.
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Sources
Flow Hive US. (n.d.). How do bees make honey? https://www.honeyflow.com/blogs/beekeeping-basics/how-do-bees-make-honey
Geiling, N. (2013, August 22). The Science Behind Honeyโs Eternal Shelf Life. Smithsonian.com. https://www.smithsonianmag.com/science-nature/the-science-behind-honeys-eternal-shelf-life-1218690/
Hanson, K. (2021, February 4). Does honey go bad or expire?. Allrecipes. https://www.allrecipes.com/article/does-honey-go-bad/
Masoura, M., Passaretti, P., Overton, T., Lund, P., & Gkatzionis, K. (2020, October 19). Use of a model to understand the synergies underlying the antibacterial mechanism of H2O2-producing honeys. Nature News. https://www.nature.com/articles/s41598-020-74937-6
The Types of Bees. PerfectBee. (2020, September 11). https://www.perfectbee.com/learn-about-bees/the-science-of-bees/the-types-of-bees
Itโs like an American accent but with calendars.