What Causes Crystallization (Sugaring) in Carob Molasses?
Sugar crystals appearing at the bottom or on the edges of the jar are a common situation encountered by those who use carob molasses. This phenomenon, popularly called "sugaring", is often interpreted as the product being spoiled or sugar being added to the molasses. However, crystallization is a process that can occur in dense sugar solutions depending on physical rules.
In this article, we discuss the sugar composition of carob molasses, how crystallization begins, what conditions can speed up this process, how to evaluate candied molasses, and how crystals can dissolve without damaging the product, based on sources.
What is Crystallization?
Crystallization is the separation of a substance dissolved in a solution from the solution by forming a regular solid structure. For sugars, the basic condition for this process is "supersaturation": When the solution contains more sugar than it can hold at that temperature, the excess sugar tends to separate into solid crystals.
Hartel and Shastry's (1991) comprehensive review of sugar crystallization in foods examines the crystallization of commercial sugars such as fructose, glucose, lactose, and sucrose under three main headings:
- Nucleation: The first formation of the crystalline phase from the supersaturated solution; It can occur spontaneously or triggered by external factors.
- Crystal growth: The crystals formed become larger by taking sugar from the solution.
- Effect of impurities and additives: Mixed sugars and other ingredients accelerate or slow crystallization.
This framework also applies to molasses. Molasses is a solution that is very rich in sugar, with most of the water removed. In a study conducted in Cyprus (Antoniou et al., 2020), it is stated that carob molasses is obtained by condensing carob must to 65–80 °Brix. In a product with such high dry matter, it is not surprising that some of the sugars turn into crystals when conditions are favorable.
Sugar Profile of Carob Molasses
In order to understand crystallization, it is necessary to know which sugars are present. The sugars of carob fruit are predominantly sucrose. In a doctoral thesis conducted at Mersin University (Yalım Kaya, 2010), it is stated that the fleshy part of the carob fruit contains 40-70 percent sugar and most of this sugar is sucrose, and the ratios vary according to the variety, region and climate.
A similar trend is observed in molasses. According to Dilek et al. (2025), who examined traditional molasses in Turkey, the TS 13717 Carob Molasses Standard stipulates that only the sucrose content should be between 20-40 percent by mass regarding sugar composition. In the same article, it is stated that in previous studies, sucrose was reported to be in the range of 22-44.38 percent, glucose 7.8-13.23 percent, and fructose 10.1-12.2 percent in carob molasses.
| Data | Sucrose | Glucose | Fructose |
|---|---|---|---|
| TS 13717 (as cited in Dilek et al. 2025) | 20–40% (m/m) | Not specified | Not specified |
| Previous studies (Dilek et al. December cited in 2025) | %22–44,38 | %7,8–13,23 | %10,1–12,2 |
| Dilek et al. (2025) Example of carob molasses | 10.66 g/100 g | 10.67 g/100 g | 17.25 g/100 g |
The last row in the table shows that sucrose was significantly lower and fructose was high in a single sample from conventional production. This difference indicates that the sugar profile of molasses can vary significantly according to production conditions. Sucrose can be broken down into glucose and fructose (inverted) in an acidic environment and under the influence of heat. A US patent (US 5,624,500) for the production of syrup from carob sugars also states that sucrose cannot be completely prevented from inverting in a strongly acidic process step and that the must should not be exposed to heat for a long time to prevent the formation of new reducing sugars during evaporation.
Why is Carob Molasses Candied?
When the above information is evaluated together, the main factors that may affect crystallization in carob molasses can be listed as follows:
- High dry matter: The thicker the molasses, the closer the sugar solution approaches the saturation limit.
- Sugar composition: The ratio of sucrose, glucose and fructose to each other affects the tendency to crystallize.
- Low temperature: The solubility of sugars decreases as the temperature drops; the cold environment increases supersaturation.
- Nucleation points: Small crystals in the jar, solid particles, or dried molasses on the rim can be the starting point for new crystals.
- Sugar addition: It is known that sugar is added to the must in some traditional productions.
For the last item, the study of Dhaouadi et al. (2014) on the production of traditional carob syrup is interesting. The researchers stated that despite the high sucrose content of carob fruit, sugar is added from time to time as a traditional practice; they stated that this addition was made to sweeten the syrup and reduce water activity for preservation, and concluded that not adding sugar is more appropriate in terms of preserving bioactive properties. Since the addition of sugar will increase dry matter, it may also affect the tendency to crystallize. However, it is not correct to conclude that not every candied molasses has added sugar; pure carob molasses can also crystallize under suitable conditions.
A clue to the role of other components in sucrose crystallization is also found in the patent mentioned above: It is stated that sucrose crystallization from carob must by the usual sugar industry methods results in low yields because reducing sugars and other impurities inhibit crystallization. This suggests that glucose, fructose and other components in molasses can slow down the crystallization of sucrose; therefore, it suggests that the change in sugar balance may affect sugaring behavior.
The Role of Storage Temperature
The rate of crystallization depends not only on composition but also on temperature. We could not find a published study that directly examined the temperature-crystallization relationship for carob molasses. However, this issue has been investigated in detail in honey, which has a similar dense sugar system. Ji et al. (2023) reported that natural crystallization occurred most rapidly at 14 °C and 16 percent water content in six different single-flowered honeys.
This result cannot be directly transferred to molasses; because honey is rich in glucose and fructose, while sucrose has a significant share in carob molasses. However, the general principle is the same: Cool but above-freezing temperatures can accelerate crystallization in some dense sugar solutions. Therefore, storing molasses in the refrigerator can make it easier to sugarcoat according to room temperature. The storage conditions specified on the label of the product always take precedence.
Is Candied Molasses Spoiled?
Crystallization is the physical separation of sugars from solution. It does not in itself mean that the product has gone bad. However, it is different if there are other symptoms along with crystallization:
| Observation | Possible meaning |
|---|---|
| Sugar crystals at the bottom or edges, normal smell and taste | Physical crystallization; the product can be used |
| Mold, cottony layer on the surface | Microbial deterioration; should not be consumed |
| Sour, alcohol-like odor, foaming, swelling of the cap | Fermentation symptom; should not be consumed |
| Pronounced burnt taste | There may be excessive heat treatment in production |
Crystallization can sometimes give an indirect clue to the quality of the product; for example, it can be seen more frequently in products that have been thickened to very high dry matter or have added sugar. However, laboratory analysis is required to say this with certainty; the presence of crystals alone is not an indication of imitation or cheating.
How Are Crystals Dissolved?
- Loosen the lid of the jar slightly and place the jar in a bowl of warm water (bain-marie).
- Keep the water at a warm-hot level without boiling and stir the molasses from time to time.
- When the crystals have dissolved, remove the jar from the water and let it come to room temperature.
- Remove any remaining crystals from the jar edges; these can be the starting point for new crystallization.
- Heat as much as you need; avoid heating the entire jar repeatedly.
The reason for avoiding high heat is that heat treatment can change the composition of molasses. According to Dilek et al. (2025), HMF is not generally found in fresh and unprocessed foods; it is reported to increase under conditions such as heat treatment and long-term storage. Boiling molasses directly on the stove or heating it at high power for a long time is therefore not recommended.
Practical Tips for Reducing Sugariness
For home use:
- Store molasses tightly closed under the conditions indicated on the label, usually in a cool, dry place.
- Do not insert a wet or touched spoon into the jar.
- Wipe the dried molasses on the jar mouth and lid.
- When crystallization begins, use it by stirring or dissolve it by heating it gently.
For the manufacturer, keeping the dry matter controlled and consistent across batches, monitoring the heat treatment in terms of time and temperature, and keeping the packaging clean during filling help reduce crystallization and other quality problems. Production stages of carob molasses What is Carob Molasses and How is it Made? We explained it in detail in our article.
Frequently Asked Questions
Can candied carob molasses be eaten?
If there are no other problems with smell, taste and appearance, crystallization alone does not mean spoilage. If there is mold, sour smell or foaming, the product should not be consumed.
Does sugaring indicate that sugar is added to molasses?
No, it does not show on its own. Pure carob molasses can also crystallize in high dry matter and suitable conditions. The presence of added sugar can only be understood by analysis.
Is it OK to store molasses in the refrigerator?
The recommendation on the label should be followed. Cold environment can facilitate crystallization as it reduces the solubility of sugars.
Can microwaves be used to dissolve crystals?
High and uncontrolled heat is not recommended. Slow heating in a warm water bath is a more controlled method.
Carob Products with Carob Türkiye
Candying in carob molasses is a physical process that often stems from the nature of the product. With proper storage and gentle heating, molasses can be easily restored to its original consistency.
At Carob Türkiye, we supply carob fruit, crumbs, flour/powder, kernels, and extracts. Businesses looking for raw materials for molasses and must production Carob Fruit, Carob Kibble (Granular) and Carob Extract You can review our pages. For your wholesale and export requests Contact Now You can contact us on our page.
Domestic resources
Dilek, N. M., Babaoğlu, A. S., Ünal, K., Turan, M., Pırlak, L., Karakaya, M., "Nutritional Profile and Functional Characteristics of Various Types of Traditionally Produced PEKMEZ—Part I", Food Science & Nutrition, 13(7), e70662, 2025. doi.
org/ 10. 1002/ FSN3. 70662 Yalım Kaya, S., "Production of high purity sugar syrup from carob fruit", PhD Thesis, Mersin University Institute of Natural and Applied Sciences, 2010 (YÖK Thesis No: 283071). Tezara.
org/ theses/ 283071 Foreign sources
Hartel, R. W., Shastry, A. V., "Sugar crystallization in food products", Critical Reviews in Food Science and Nutrition, 30(1), 49–112, 1991. doi.
org/ 10. 1080/ 10408399109527541 Antoniou, C., Kyratzis, A., Rouphael, Y., Stylianou, S., Kyriacou, M. C., "Heat- and Ultrasound-Assisted Aqueous Extraction of Soluble Carbohydrates and Phenolics from Carob Kibbles of Variable Size and Source Material", Foods, 9(10), 1364, 2020. doi.
org/ 10. 3390/ foods9101364 Dhaouadi, K., Belkhir, M., Akinocho, I., Raboudi, F., Pamies, D., Barrajón, E., Estevan, C., Fattouch, S., "Sucrose supplementation during traditional carob syrup processing affected its chemical characteristics and biological activities", LWT – Food Science and Technology, 57, 1–8, 2014. doi.
org/ 10. 1016/ j. lwt. 2014. 01. 025 Sanjuan Diaz, C. (inventor), "Syrup of natural carob sugars and a process for its production", U.S. Patent U.S. 5,624,500 A, 1997. patents.
google. com/ Patent/ US5624500 Ji, P., Liu, X., Yang, C., Wu, F., Sun, J., Cao, W., Zhao, H., "Natural crystallization properties of honey and seed crystals-induced crystallization process for honey performance enhancing", Food Chemistry, 405(Pt B), 134972, 2023. doi.
Scientific Resourcesorg/ 10. 1016/ j. foodchem. 2022. 134972
