Why Is Honey Pasteurized?

Honey found on supermarket shelves is pasteurized because pasteurization makes the honey last longer. Pasteurization involves using heat to slow down the natural process of granulation, keeping the honey in liquid form for longer.  It also destroys yeast spores that may cause the honey to ferment.

What Is Pasteurization?

Pasteurization is the method of using heat to eliminate harmful microorganisms that may be present in foods, therefore extending their shelf life. The process was invented by French chemist Louis Pasteur in the 1800s. He discovered that applying heat to wine deactivated unwanted microorganisms and prevented it from spoiling. Pasteurization is now used in a wide variety of foods and drinks, including dairy products such as milk.

Because honey has a low moisture content and a high level of acidity, bacteria and other possibly harmful organisms can’t reproduce in it. Therefore, honey isn’t pasteurized for this purpose. Instead, honey is pasteurized for other reasons.

Assembly line showing honey being pasteurized in a factory
Honey is pasteurized before being sold in supermarkets

Why Is Honey Pasteurized

Honey is pasteurized for three main reasons:

To Kill Yeast Cells

Yeast cells are present in honey, however, because of honey’s low moisture content, they are usually inactive. The moisture content of honey is usually between 14% and 18%, sometimes as high as 20%, but this depends on the nectar source.

All floral nectar contains osmophilic yeasts which are likely to reproduce when the moisture content of honey is above approximately 18%, and therefore cause fermentation of the honey. However, this also depends upon the number of yeast spores present in the honey in the first place.

Pasteurization kills the yeast spores in the honey and therefore removes the possibility of it becoming fermented.

Fermented honey shouldn’t be fed to bees because it can cause dysentery, but it’s generally okay for us to eat. However, bear in mind the taste will be different and be aware it may have become contaminated in some other way during the filtering and packaging process.

To Delay Crystallization

Crystallization, otherwise known as granulation or candying of honey, is a natural process that does not mean the honey is spoiled in any way. The glucose in honey can form crystals and over time they will become a solid layer.

Cloudy honey
Unpasteurized honey can crystallize and become cloudy

The honey derived from various floral sources will form crystals of different sizes, from fine to coarse. Also the rate at which they form crystals varies.

Temperatures below 50 degrees Fahrenheit (10 degrees Celsius) and above 57.2 degrees Fahrenheit (14 degrees Celsius) slow down the rate of crystallization.

In addition to sugar crystals, very small particles of dust, wax and pollen may be present in the honey. These particles can accelerate crystallization by acting as nuclei around which the sugar crystals can form.

This is why honey is pasteurized and filtered before being packaged and sold. Pasteurization dissolves any fine sugar crystals present and filtration removes the particles of dust, pollen and wax.

To Extend Shelf Life

Pasteurization extends the shelf life of honey by killing yeast spores (to prevent fermentation) and delaying the natural process of crystallization. Honey for sale has more appeal to the consumer if it is viscous and not crystallized.

However, honey that has crystallized can easily be made liquid again by gently heating the honey container, between 130 degrees and 140 degrees Fahrenheit (54 and 60 degrees Celsius) in warm water and stirring it thoroughly.

Remember too that the yeast spores in honey only become active when the moisture content is above 18%.

Raw Honey Vs Pasteurized Honey: What Is The Difference?

There are a few differences between raw honey and pasteurized honey that should be noted if you’re undecided about which one to have:

  • Raw honey contains antioxidants and micronutrients that are beneficial to health and has also been used to treat wounds. It’s believed that some of these health-giving properties may be affected or destroyed by pasteurization.
  • Raw honey is often cloudier than pasteurized honey because it contains tiny pieces of honeycomb or wax that are too small to be filtered out.
  • Raw honey is viscous because it flows slowly at room temperature. After pasteurization, honey becomes less viscous and flows more easily, but care must be taken not to overheat it so it becomes spoiled.
  • Raw honey has more variety in color and texture than pasteurized honey because of the types of flowers in bloom at the time the bees visited to collect nectar.

How To Tell If Honey Is Raw Or Pasteurized

It can be difficult to tell whether honey is pasteurized or raw just by looking at it. However, there are a few clues that may give you the answer:

  • If the honey has commercial packaging, it is probably pasteurized (it will often say this on the packaging)
  • If the honey is stored in a jar without a label, such as a mason jar, it is probably raw, unpasteurized honey
  • If the honey has crystallized (turned hard or cloudy) it is almost certainly raw, unpasteurized honey

Another clue is where you bought the honey from – if it is sold commercially at a supermarket, it is almost certainly pasteurized honey. If it has been bought from a farmer’s market or local beekeeper, there’s a much higher chance it will be raw honey. You can always ask the person you get the honey from if you’d really like to know!

Raw honey which has crystallized or turned cloudy
Honey that crystallizes has not been pasteurized
Shelf of supermarket honey which is pasteurized before being sold
Honey from the supermarket is pasteurized

Is Raw, Unpasteurized Honey Safe To Eat?

Honey that is unpasteurized is perfectly safe to eat. Although pasteurization gives honey a longer shelf life because it reduces the chance of crystallization and destroys yeast spores that may cause the honey to ferment, you can overcome both of these potential problems without having to pasteurize honey.

Firstly, crystallization can be remedied by gently heating the container of honey in a water bath and stirring it until it is liquid again.

Secondly, fermentation caused by yeast spores can be prevented by only harvesting honey that is fully ripe and storing it in an airtight container where moisture can’t enter. The yeast spores that are present in honey only become active (and cause fermentation) when the moisture content is higher than approximately 18%.

Summing Up…

Honey available on the supermarket shelves is pasteurized to prevent crystallization and fermentation, giving it a longer shelf life. However, some of the nutrient value may be lost in the process.

Unpasteurized or raw honey, on the other hand, retains its antioxidants, micronutrients and other health benefits. The only downside is that is may crystallize or ferment. Both of these potential problems can be overcome by keeping the honey in an airtight container to prevent moisture entering, and by gently heating the honey should it crystallize.

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