Honey Crystallisation Speed Predictor

Glucose ÷ water (G/W) is the best single predictor: 1.70 or less tends to stay liquid, 2.10 or more tends to set fast. Pick a honey or enter your own lab numbers.

Your Honey

Crystallisation Prediction

Described rate
Slow

Acacia (black locust) Robinia pseudoacacia — IHC sheet: valued because it stays liquid, thanks to its high fructose. Crane's directory: G/W 1.90, slow.

Source: IHC sheets (Persano Oddo & Piro 2004)

Glucose ÷ water
1.57
G/W 1.70 or less: likely to stay liquid

White et al. (1962) found G/W of 1.7 and lower generally goes with honey that does not granulate; in their survey, honeys with no granulation after 6 months averaged 1.58. In Manikis & Thrasyvoulou (2001), all 6 Greek thyme samples in this range were still liquid at 17 months.

1.2stays liquid ≤ 1.70sets fast ≥ 2.102.6
Fructose ÷ glucose (F/G)
1.61
F/G between 0.90 and 1.66: in Manikis & Thrasyvoulou (2001), F/G in this range predicted nothing (it was right for only 10–14% of honeys).

Measured Honey Types

HoneyG/WF/GDescribed rateSource
Rape (canola)2.370.95FastIHC
Dandelion2.330.99FastIHC
Sunflower2.101.05FastIHC
Clover1.501.33Fast *Crane
Eucalyptus2.141.19Moderate *IHC
Rosemary2.061.16ModerateIHC
Linden (lime)1.931.18ModerateIHC
Citrus (orange blossom)1.921.24ModerateIHC
Thyme1.901.41ModerateIHC
Lavender1.881.18ModerateIHC
Rhododendron1.791.29ModerateIHC
Heather1.761.26ModerateIHC
Chestnut1.621.48SlowIHC
Honeydew1.611.25SlowIHC
Buckwheat1.610.99SlowCrane
Acacia (black locust)1.571.61SlowIHC
Sourwood1.531.59SlowCrane
Metcalfa honeydew1.511.34SlowIHC
Tupelo1.361.77Does not crystallizeCrane

IHC = mean of the International Honey Commission descriptive sheets (Persano Oddo & Piro 2004). Crane = single value per plant from Crane et al. (1984) in Manikis & Thrasyvoulou (2001), Table I; Crane's classes mean fast = complete within 1 month, moderate = 1–12 months, slow = over a year. * the G/W rule puts this honey in the wrong class.

Related Tools

Honey Crystallization TimelineG/W by described rate, and months for 18 Greek thyme samplesHoney Fermentation Storage Risk CalculatorMoisture × temperature × time → fermentation risk verdictHoney Brix Refractometer CalculatorConvert Brix reading to moisture % and water activity

Frequently Asked Questions

Why does some honey crystallise in weeks while other honey stays liquid for years?+
Glucose is the sugar that forms the crystals, and the best single predictor is how much glucose the honey holds for its water: the glucose-to-water (G/W) ratio. White et al. (1962, USDA) found G/W of 1.7 or lower generally goes with honey that does not granulate, and 2.1 or higher predicts rapid granulation to a solid; Manikis & Thrasyvoulou (2001) used the same cut-offs and were right for 93% of Greek and 68% of imported honeys. Tupelo (G/W 1.36 in Crane's directory) does not granulate; rape (canola) honey, with a mean G/W of 2.37 in the International Honey Commission sheets, sets fast.
Is the fructose-to-glucose ratio a good predictor?+
Only at the extremes. Manikis & Thrasyvoulou (2001) found F/G predicted crystallisation correctly for only 10–14% of honeys and was useful only above 1.66 (slow) or below 0.90 (fast). Use G/W instead.
Can this tool tell me when my jar will crystallise?+
No. The sources give a described rate, not a date, for most honeys. The one month-by-month record we found is 18 Greek thyme honeys in Manikis & Thrasyvoulou (2001): samples with G/W of 1.70 or less were still liquid at 17 months, and most samples above it crystallised after 11 to 16 months. Storage temperature, moisture and seed crystals all move a single jar.
Does crystallised honey go bad?+
No. Crystallisation is a physical change: glucose comes out of solution and forms crystals. It does not make honey unsafe. To re-liquefy, stand the jar in a 35–43 °C (95–110 °F) water bath for 30–60 minutes; avoid the microwave.
How do I embed this crystallisation predictor on my website?+
Paste this HTML: <iframe src="https://rawhoneyguide.com/tools/honey-crystallization-predictor" width="100%" height="2500" frameborder="0" loading="lazy" title="Honey Crystallisation Speed Predictor"></iframe>. For a dark-theme version, append ?theme=dark to the src URL.

Data: Persano Oddo & Piro 2004 · Manikis & Thrasyvoulou 2001 · White et al. 1962

Raw Honey Guide · A described rate is for the pure honey type; moisture, storage temperature and seed crystals change a single jar.