92% of honey is composed of levulose (also referred to as Fructose), dextrose (also referred to as glucose) and water. The ratio of levulose, dextrose, water and the remaining other 8% of various sugars etc. is different for each source of nectar. This is why each honey has a unique flavor, aroma, body and color.
Nectar is mostly water, much of which is evaporated by the bees in the curing process of the honey. As the honey cures it becomes a supersaturated sugar solution. This means that the solution contains more sugar then would naturally dissolve into water at that temperature. Even if the honey is not supersaturated at the hive temperature of 95 degrees, it becomes supersaturated when it is cooled to room temperature. This is because sugar is more soluble in warmer water then in cooler water. Dextrose is less soluble then levulose and has a strong tendency to precipitate (form crystals) from a supersaturated solution.
Honey crystallizing is the process of dextrose reverting from a dissolved solution form into a solid crystal form. Some honey, such as mustard honey, has a higher percentage of dextrose and will crystallize very quickly. Some honey, such as sage honey, has a higher percentage of levulose and will crystallize very slowly. Honey does not spontaneously crystallize; the crystals must grow on a seed surface. This is why commercial packing plants filter honey, removing any small particles from the honey, eliminating many of the seeds upon which the crystals may grow. Heating honey also dissolves any microscopic crystals that are too small to be seen, removing them as seed surfaces.
Raw honey has an abundance of seed surfaces as it is loaded with pollen, microscopic dextrose crystals, and bits of wax and propolis. It will crystallize relatively quickly as compared to commercially heated and filtered honey. If crystallized honey is warmed, the dextrose becomes more soluble and will return to solution, that is why heating crystallized honey will return it to its liquid state. You can't just heat it to the hive temperature of 95 degrees and expect all of the sugar crystals to return to solution though, because the honey was supersaturated at that temperature. The honey must be warm to a higher temperature to where the water will naturally desolve all the available sugar. That is why I warm the honey to 115 degrees and not just 95 degrees when I re-liquify it. I am unwilling to warm honey beyond 115 degrees and still call it raw. Some honeys will not full return to solution at 115 degrees and there will be a thin layer of crystallized dextrose in the bottom of the jar. Once re-liquefied the honey generally remains in the liquid state for a month and a half or more if stored at 70 degrees. If stored in the freezer the honey will remain in the liquid state for many months. It will re-crystallize very quickly if stored between 55 to 60 degrees.
Sadly the answers to the first question is no. Contrary to the popular belief that honey keeps forever; moisture makes it prone to spoilage just like any other food product. Water is the one common, necessary component for all living things on earth. Honey is hygroscopic, that means that it will attract and hold water molecules from the surrounding environment. Honey absorbs moisture from organism within it, if the honey has a low moisture content it will absorb so much water as to result in the organism's death or at least prevent it from multiplying. This is one of the ways that it acts as an antibacterial agent. If the moisture content of honey is below 17.1 percent, even sugar tolerant yeasts are inactivated so the honey is safe from the possibility of fermentation. Unfortunately the yeast is not killed and if the honey is raw the yeast may become active if the moisture content rises sufficiently.
92% of honey is composed of dextrose, levulose and water with the remaining 8% being other sugars and the various components that give each honey its unique flavor. Crystallization will occur in almost all honey over time as the less soluble dextrose leaves solution and forms dextrose crystals. As dextrose leaves the solution, the ratio of water to the remaining sugars in solution increases. When enough dextrose has left the solution the moisture content of the solution will become more favorable to the yeast and fermentation becomes possible. The ways to prevent fermentation when this occurs is to either store the honey below 50 degrees, at temperatures low enough to inactivate the yeast, or to re-liquefy the honey so that the moisture/sugar ratio returns to a moisture content below 17.1 percent thereby inactivating the yeast.
Commercial honey packers prevent fermentation through pasteurization, heating the honey to 160 degrees killing the yeast. I believe that the high heat necessary to pasteurize the honey may destroy much of what is good in the honey and that it is better to keep it raw. I have found that warming honey to 115 degrees for several hours is enough to get most of the dextrose to return to solution, stop fermentation and preserve the good qualities of the honey.
Some people believe that if the honey is warmed at all it is not raw. This may be technically true but honey in the hives of the California central valley and desert region experiences temperatures of 115 degrees while still in the hive. It is preferred to eat raw honey just as it is when comes from the comb, if it crystallizes the risk of fermentation increases dramatically and can readily be observed. When fermentation is beginning or is likely to begin, it is far better to warm the honey and re-liquefy it to stop and prevent fermentation, and preserve the good qualities of the honey, rather then losing the honey altogether to fermentation. Any and all of my honey that has been warmed are clearly labeled with a label saying "This Honey has been warmed to 115 degrees F to re-liquify". If there is no such label then it has not been warmed. I estimate that about 10% of my honey gets warmed before being sold, mostly in the late summer. I consider the warmed honey to be raw, but if you do not then avoid the bottles that indicate that they have been warmed.
The main causes of honey spoilage are fermentation and heat. Fermentation is the production of ethyl alcohol and carbon dioxide by yeast as it grows and feeds on sugar. The ethyl alcohol may then break down into acetic acid (vinegar) and water in the presents of oxygen. The combined flavors of yeast, alcohol and acetic acid make the honey unpalatable. A number of physical changes also occur within the honey changing its physical characteristics as it ferments.
The yeasts responsible for fermentation are endemic throughout our environment. They are present in all honey that has not been pasteurized. The risk of fermentation is dependant on both the moisture content and yeast spore concentration within the honey and on the temperature at which the honey is stored. According to US agriculture handbook number 335 Beekeeping In The United States
"Honey with less than 17.1 percent water will not ferment in a year, irrespective of the yeast count. Between 17.1 and 18 percent moisture, honey with 1000 yeast spores or less per gram will be safe for a year. When moisture is between 18.1 and 19 percent, not more than 10 yeast spores per gram can be present for safe storage. Above 19 percent water, honey can be expected to ferment even with only one spore per gram of honey, a level so low as to be very rare."
"If honey has more than 17 percent moisture and contains a sufficient number of yeast spores, it will ferment. Such honey should be pasteurized, that is, heated sufficiently to kill such organisms."
Since fermentation is also dependant on temperature it is assumed that the above quotes are for storage at room temperature. Moist honey will not ferment when stored below 50 degrees F or above 80 degrees F. Storing honey at temperatures above 80 degrees F to prevent fermentation is not recommended, the high temperature will damage honey in other ways that are equally objectionable. I recommend that consumers store their honey at room temperature if it will be consumed within 3 months. If your container of honey is too large to be consumed within three months then it should be divided into smaller containers and those that are not in use should be stored in the freezer or refrigerator, only the container of honey in use should be stored at room temperature.
Honey is extremely hygroscopic, that means that it will attract and hold water molecules from the surrounding environment. If it is left unsealed it will absorb moisture from the air and start to ferment at the top surface of the honey. This is not as easily identified as in crystallized honey so make sure you keep you honey jar sealed.
US grade A honey has a moisture content of not more than 18.6%. Yeast cannot grow unless the moisture content is above 17% and grows poorly between 17 and 18.5 percent, depending on the number of yeast spores present. What this means to the consumer is that Raw (not pasteurized) US Grade A honey with a moisture content of greater than 17% will likely keep for several months at room temperature without any adverse spoilage due to fermentation, longer periods of storage at room temperature may result in spoilage. When stored at temperatures less than 50 degrees Fahrenheit yeast cannot grow, so fermentation cannot occur and raw honey will keep for many months or years. My honey typically has a moisture content between 16 and 17 percent so it is generally safe from fermentation as long as it is not crystallized.
The relative moisture content in stored honey can increase in one of two ways. Either moisture is added to the honey by being absorbed from the environment or some sugar is removed from the honey sugar solution through crystallization, causing the relative moisture content of the remaining sugar solution to increase.
Raw honey tastes better than, and is much better for you than, conventional commercially packaged honey. Unfortunately raw honey is also much more susceptible to fermentation than conventional commercially packaged honey. That is because commercially packaged honey that is not raw, has been pasteurized to kill the yeast, and has been filtered to remove most seed material that aids crystallization.
Much of the raw honey available from large-scale suppliers is from desert areas where it is very hot and dry. Honey from these regions can have a very low moisture content. Even after crystallizing the remaining sugar solution moisture content in desert honey may be low enough to prevent fermentation. If you want a long keeping raw honey with less likelihood of fermentation, shop for honey from a desert area.
Raw honey from cool, moist, foggy areas like the Monterey Bay area has a higher moisture content then desert source honey. It is particularly susceptible to fermentation when it has crystallized. If you live in the central coast area of Monterey Bay, want all the benefits of raw local honey, with a marvelously delicious taste that you can find no where else, then buy from a local beekeeper that produces raw honey and learn how to identify the signs of, and how to stop, fermentation of honey.
There is absolutely nothing wrong with crystallized honey. Many of us that like raw honey, like it better when it is crystallized. Creamed, spun, and whipped honey, are all names for crystallized honey with crystals so small that it has butter like texture. Don't stress when your honey crystallizes you might even like it better that way. What you do need to do is learn to know the signs of fermentation and stop it before the honey is spoiled.
You can greatly retard the crystallization process by placing honey in the refrigerator of freezer. This makes the honey so thick that it is hard for the dextrose molecules to move to a crystal and leave the solution. Storing the honey below 50 degrees F also has the benefit of preventing fermentation during the period of storage by inactivating the yeast. Unfortunately it also makes the honey so thick that it is very hard to use. I recommend keeping your honey in the freezer if you have a jar that you are not going to open for a while. You can assure that fermentation will not occur by re-liquefying the honey whenever there are signs of crystallization. This will work but keep in mind that over heating the honey or heating it for long periods of time will degrade the taste and the beneficial aspects of raw honey. To maintain the most benefit of the honey it most be warmed is little as possible for as sort a time as necessary. See How To Re-liquefy Crystalized Honey
As yeast grows it produces carbon dioxide gas. The carbon dioxide gas forms bubbles that push the sugar solution away from the dextrose sugar crystals making them visible. The sugar crystals will appear as light areas in the crystallized honey, forming feathery fractal like patterns. The longer it ferments the larger these light regions will grow.
In the top photo to the left we are looking through the bottom of a jar of honey that has been allowed to ferment to the pont or ruin. In the bottom photo to the left we are looking into the honey through the top of the same jar. The areas of fermentation are obvious by the light colored areas that the carbon dioxide bubbles cause.
Never allow fermentation to get as far along as that shown in the pictures or the honey is spoiled and must be discarded. The skill to learn is how to identify the gas bubbles and re-liquefy the honey before the fermentation goes on long enough to spoil the honey. When you see any signs if fermentation the honey should be re-liquefied as soon as possible. The moisture content of the sugar solution will again be below 18.5% stopping the fermentation. When you have had to re-liquefy a jar of honey to stop it from fermenting, then you know that particular jar of honey will ferment when crystallized and it should be used as soon as possible, re-liquefied whenever it is showing signs of crystallizing or be stored in the freezer or refrigerator to slow the crystallizing.
If you suspect that the honey might be fermenting but are not sure, re-liquefy the honey. If there is any foam on top of the honey after it is liquified then it was fermenting. The foam is caused by the carbon dioxide bubbles as they are released from the crystalized honey. The photo on the right is of the same jar on the left after it is re-liquefied. As you can see by all the foam and the bubbles in the honey, the honey is badly fermented.
Below are additional pictures of fermenting honey that I came across in a health food store. Look carefully at crystalized honey that you are about to purchse to check for signs of fermentation before you buy it.
Above are additional pictures of fermenting honey that I came across in a health food store. Look carefully at crystalized honey that you are about to purchse to check for signs of fermentation before you buy it.
To re-liquefy crystallized honey, the honey needs to be warmed to the point that the dextrose crystals dissolve.
The quick methods:
If you use your honey primarily in hot tea, for cooking, or heat the honey to over 130 degrees in some way before you eat it, then preserving the beneficial enzymes in the raw honey is not a priority to you. You can use the quicker higher heat methods. Try to retain as much of the delicate flavors as possible by exposing the honey to the heat for as short a time as possible and cool it as soon as possible.
The microwave method: You want to get the honey so that it is just starting to liquefy and then alternately stir and apply heat until it is fully liquefied. How much honey is in the jar and the power of your microwave will determine how long you will heat it the first time, and how long to apply heat between stirrings. If you are not sure how long to heat it, start with 30 seconds for a one-pound jar and then experiment for the best times. Remove the lid and place the jar in the microwave oven for 30 seconds. Look to see if the outside portion or pockets of the honey are turning liquid. If not, heat it for another 30 seconds. When the outside is turning to liquid alternately stir the jar and apply 15 to 30 seconds of heat in the microwave. The thing to remember about a microwave oven is that the outside gets most of the heat, and the inside gets very little. You can ruin the outside portion of the honey with the inside still cold, unless you stir it frequently. It is the stirring that distributes the heat more evenly. Once the honey is liquid look through the honey from the side. If you see a lot of crystals floating throughout it, heat it again until they are all dissolved.
The hot water method: This is the traditional method of liquefying honey used before we had microwaves. It is basically the same process but we are heating the outside of the jar with hot water. It is also a little gentler then the microwave as we can control how hot the water is and the heat is uniformly applied to the outside of the jar. Find a saucepan that is taller then the jar. Place the jar in the pan and fill the pan with hot tap water (not water heated from a tea pot, that's too hot) so that the water line is above the honey line in the jar. Remove the honey jar lid and put the pan on the stove burner on medium to low. When you see the honey on the outside of the jar starting to liquefy stir the honey, heat the water for another minute and then turn off the burner. Stir the honey every few minutes until the honey is fully liquefied (when no crystals can bee seen when you look through the jar from the side). If the jar is particularly large you may have to turn on the burner again for a few minutes as the jar takes heat from the water.
The gentle but slow methods:
If you eat the honey cold by the spoon full, or in such a way that the honey is not heated over 130 degrees Fahrenheit before you eat it, then it may be important to you to preserve the beneficial enzymes in the raw honey. In this case it will take several hours and some monitoring to fully re-liquefy the honey. The honey will need to be exposed to low heat of less than 130 degrees for several hours of more. I have a specially constructed warming box with precision temperature control that can warm many jars at a time to 115 degrees Fahrenheit. Unfortunately you do hot have this option.
I have not yet tried these methods but wish to suggest them for those that wish to try them. I will update the web site as soon as I have verified the methods.
Yogurt Maker:Yogurt makers hold the temperature at around 112 degrees Fahrenheit. Transfer the honey to a jar that will fit in the yogurt maker if necessary. Leave the jar in the yogurt maker for about 6 hours and check it to see if it is completely liquefied. If not leave it another 4 to 6 hours. If after this amount of time it is not fully liquefied then the yogurt maker is not hot enough.
Oven method:I made yogurt with this method before I had a yogurt maker. Get a deep oven safe pan. Pre Heat the oven at the lowest temperature available. The idea is to get the interior oven walls up to over 120 degrees Fahrenheit. Now turn off the oven. (Don't leave it on). Put the jar of honey in the pan and fill the pan with hot tap water of 120 to 125 degrees so that the water is over the honey line. Put the pan in the oven and close the door. Check the water temperature in about 2 hours. If it is below 115 degrees replace the water and re-warm the oven. I would usually do this in the evening and then leave it in the oven over night.