Syrup is a thick, viscous liquid that is commonly used as a topping or ingredient in foods and beverages. Syrups are made by dissolving sugar in water, which increases the viscosity. The viscosity of syrup refers to its thickness and resistance to flow. Syrup can range from thin and pourable to very thick and sticky depending on the sugar content. So is syrup considered a high or low viscosity liquid?
What is viscosity?
Viscosity is a measure of a fluid’s resistance to flow. It refers to the internal friction within a liquid that makes it resist motion and flow. Thicker, stickier fluids have higher viscosity while thinner, more watery fluids have lower viscosity. Viscosity is measured in units called centipoise (cP). Liquids with viscosity below 100 cP are considered low viscosity while liquids with viscosity above 1000 cP are considered high viscosity.
Typical viscosity ranges
Here are the typical viscosity ranges for some common liquids:
| Liquid | Viscosity Range (cP) |
|---|---|
| Water | 1 |
| Milk | 3 |
| Olive oil | 80-100 |
| Honey | 2000-10000 |
| Chocolate syrup | 5000-10000 |
| Molasses | 5000-10000 |
| Maple syrup | 2000-3600 |
| Corn syrup | 800-6000 |
As you can see, syrups like chocolate syrup, molasses, and maple syrup have quite high viscosity ranging from 2000-10000 cP. On the other hand, corn syrup has a lower viscosity ranging from 800-6000 cP. So most syrups would be considered high viscosity liquids.
What factors affect syrup viscosity?
There are a few key factors that determine the thickness and viscosity of syrup:
Sugar content
The main factor is the amount of dissolved sugars. Sugars increase the viscosity of water by forming long molecular chains that entangle and resist flow. Syrups with higher sugar content will be thicker. For example, pure maple syrup contains about 60-70% sugar while corn syrup only contains 24-42% sugar. The more sugar dissolved, the less freely the syrup molecules can move, resulting in higher viscosity.
Temperature
Temperature also affects syrup viscosity. Viscous liquids tend to get thinner when heated as the molecular chains move more freely at higher temperatures. So syrups will have lower viscosity when warm compared to when refrigerated and cold. This is why syrup bottles recommend warming before use if refrigerated.
Type of sugar
Different sugars have different effects on viscosity. Larger sugar molecules like sucrose and glucose form longer molecular chains which increase viscosity more than smaller sugars like fructose. So syrups made with sucrose sugar will be thicker than ones made with fructose.
Water content
The amount of water also impacts viscosity. The more water in the syrup, the lower the viscosity will be. Diluting syrup with extra water decreases its thickness and resistance to flow.
Viscosity of common syrups
Maple syrup
Pure maple syrup has a viscosity ranging from 2000-3600 cP depending on grade. This thick, sticky consistency comes from maple syrup being made of about 60-70% sucrose sugar as well as the presence of large phenolic compounds. It is considered a high viscosity syrup.
Molasses
Molasses syrup is extremely viscous with a consistency like glue, ranging from 5000-10000 cP viscosity. It contains a high concentration of large sugar molecules like sucrose and glucose oligomers that stick together strongly. The purity and sugar content increases with darker molasses. The thick viscosity makes it difficult to pour.
Honey
Honey is also a very thick and viscous syrup with a viscosity of 2000-10000 cP. It contains around 80% sugar primarily in the form of fructose and glucose. Honey’s viscosity comes from low water content and the presence of complex proteins, enzymes, and colloidal particles in suspension.
Chocolate syrup
Chocolate syrup has a viscosity similar to honey ranging from 5000-10000 cP. It derives thickness from high sugar concentrations up to 76% as well as chocolate particles and emulsifying agents like lecithin. Corn syrup is often added to improve mouthfeel and viscosity.
Corn syrup
Corn syrup has the lowest viscosity of common syrups, ranging from 800-6000 cP. It is made nearly entirely of glucose syrup which does not crystallize easily. The viscosity depends on the level of conversion from starch. Higher maltose glucose content results in thicker syrup.
Golden syrup
Golden syrup has a viscosity around 6000 cP, thicker than corn syrup but not as viscous as maple. It is made by refining sucrose into invert sugars like fructose and glucose. The residual sucrose and high sugar concentration of 60-70% contribute to its moderately high viscosity.
Caramel syrup
Caramel syrup can range from 2000-5000 cP depending on ingredients. It gets viscosity from high sugar content as well as the caramelized sugar particles dispersed throughout. Additional corn syrup may be added to make it thicker and inhibit crystallization.
How syrup thickness affects use
The viscosity of syrup affects its functionality and use in cooking:
Coating ability
Thicker syrups with higher viscosity cling better and coat foods more evenly. Lower viscosity syrups like corn syrup run off foods more easily.
Layering
Highly viscous syrups hold distinct layers and patterns when poured without mixing or diffusing together quickly.
Drizzling
Low viscosity syrups flow in a thin, steady stream making them ideal for delicate drizzling. High viscosity syrups drizzle inconsistently in thick globs.
Mixing
Thin syrups readily mix into drinks or batters. Thick syrups may need dilution or heat to blend smoothly.
Sticking
High viscosity helps syrups like honey and molasses remain stuck to surfaces. Low viscosity syrups drip and slip off surfaces more readily.
Mouthfeel
Syrup thickness significantly impacts the mouthfeel and eating experience. Thin syrups feel smooth while thick viscous syrups are luxuriously sticky and rich on the tongue.
Conclusion
In summary, most common syrups like maple, chocolate, honey, and molasses have high viscosity ranging from 2000-10000 cP. Their thick consistency comes from high sugar concentrations and large sugar molecules that entangle. Corn syrup has lower viscosity around 800-6000 cP. Syrup viscosity is affected by factors like sugar content, temperature, sugar type, and water concentration. Thicker syrups tend to coat foods more evenly while thinner syrups mix and drizzle more smoothly. The viscosity of syrup significantly impacts its functionality in cooking and baking applications as well as mouthfeel.
