|WATER-IN-HONEY - MEASURING THIS ASPECT OF HONEY QUALITY
The water content of honey (water-in-honey) is the quality aspect that determines the ability of honey
to remain fresh and to avoid spoilage by yeast fermentation. Raw honey can have a water-in-honey
content of less than 14% and the lower the water content the higher the perceived value of the honey. It
is internationally recognized that good quality honey should be processed at less than 20% water
content. Low water content is desirable because honey may begin to ferment and lose its fresh
quality if the water-in-honey is greater than 20%. Unpasteurized honey ferments because it contains
wild yeast. However, due to honey's high sugar concentration these yeasts are less likely to cause
fermentation in honey with low water content. The honey's low water content causes the yeast to
enter its dormant stage preventing the fermentation process. In honey with high water content the
yeast is more likely to cause fermentation during storage resulting in higher acidity directly affecting
the honey's quality.
Honey easily absorbs water from the air. This means that it can be difficult to produce good quality
honey with low water content in areas where humidity is high. Because honey's water content greatly
affects the possibility of fermentation during storage and thus the quality of the honey, the measurement
of the water content in honey very important. To control this factor it is important that water
content be known with a good degree of accuracy. Bee keepers in the field will regularly visit the
beehive, extract honey from the comb, and use a water-in-honey refractometer to measure the concentration
of water in the honey. As time progresses and the bees 'work the honey,' the water will be driven
away leaving a thick syrup. When the honey reaches the desired concentration, it can be removed
from the comb for processing.
Water-in-Honey Refractometers are simply high range sugar refractometers that have an 'inverted scale;'
that is, instead of expressing the sugar content in water, the scale shows 'water in sugar.' While
the water-in-honey refractometer doesn't yield the true water content, it is a very simple and reproducible
method which has been successfully used up to this point in measuring honey quality.
Honey quality and water content can vary widely from hive to hive and even from cell to cell. Additionally
honey that has been stored for some time will have a moisture content gradient with less moister at the
surface than at the bottom. This means that prior to testing with a water-in-honey refractometer
ensure that the honey is well mixed. Because of possible human error or honey sample differences
it is recommended that multiple water-in-honey refractometer readings be taken to ensure that a correct
reading is made.
For more information on hand held refractometers which can provide water-in-honey measurements please
see the E-line optical refractometer, and
Eclipse hand held refractometer web pages.
Every effort has been made to ensure the accuracy of the contents of this FAQ. However, Xylem Inc.
can assume no responsibility for errors contained in this FAQ.